fibrin and Venous-Thrombosis

As the third most common vascular disease, venous thromboembolism is associated with significant mortality and morbidity. Pathogenesis underlying venous thrombosis is still not fully understood. Accumulating data suggest fibrin network structure and factor XIII-mediated crosslinking are major determinants of venous thrombus mass, composition, and stability. Understanding the cellular and molecular mechanisms mediating fibrin(ogen) and factor XIII production and function and their ability to influence venous thrombosis and resolution may inspire new anticoagulant strategies that target these proteins to reduce or prevent venous thrombosis in certain at-risk patients. This article summarizes fibrinogen and factor XIII biology and current knowledge of their function during venous thromboembolism.

Topics: Blood Coagulation; Factor XIII; Fibrin; Fibrinogen; Hemostatics; Humans; Thrombosis; Venous Thromboembolism; Venous Thrombosis

The presence of a vascular access device (or of any intravascular foreign body) inside the bloodstream is often associated with the formation of a connective tissue sleeve around the catheter (often named-erroneously-"fibrin sleeve"). Such sleeve is usually a physiological phenomenon with little or no clinical relevance, but its pathogenesis is still unclear, so that it is frequently confused with venous thrombosis; also, its relationship with other major catheter-related complications, such as venous thrombosis and bloodstream infection, is uncertain. This narrative review tries to convey in a systematic form the current knowledge about pathogenesis, incidence, clinical manifestations, diagnosis, and management of this phenomenon.

Topics: Catheterization, Central Venous; Catheters, Indwelling; Fibrin; Foreign Bodies; Humans; Venous Thrombosis

Diseases such as myocardial infarction, ischaemic stroke, peripheral vascular disease and venous thromboembolism are major contributors to morbidity and mortality. Procoagulant, anticoagulant and fibrinolytic pathways are finely regulated in healthy individuals and dysregulated procoagulant, anticoagulant and fibrinolytic pathways lead to arterial and venous thrombosis. In this review article, we discuss the (patho)physiological role and laboratory assessment of fibrin, factor XIII and endogenous fibrinolysis, which are key players in the terminal phase of the coagulation cascade and fibrinolysis. Finally, we present the most up-to-date evidence for their involvement in various disease states and assessment of cardiovascular risk.

Topics: Factor XIII; Fibrin; Fibrinolysis; Humans; Thrombosis; Venous Thrombosis

The number of people infected with human immunodeficiency virus (HIV) is rapidly increasing and the majority of those infected are living in sub-Saharan Africa. Some hallmarks of HIV are inflammation and upregulation of inflammatory markers. A pathological coagulation system may accompany these inflammatory changes and potentially result in venous thromboembolism such as a deep vein thrombosis (DVT). In this review, the authors describe the inflammatory profile in HIV, the treatment regimens currently in place in South Africa, and in particular how HIV affects the hematological system, with specific focus on platelets, red blood cells (RBCs; erythrocytes), and fibrin(ogen). They also discuss the presence of DVT in HIV, focus on screening tests, and suggest a more proactive approach to track the inflammatory profile of HIV patients, by specifically using parameters that might point to pathological coagulation; these should involve platelet, RBC, and fibrin(ogen) analysis. They conclude by suggesting that including coagulation function tests to study the effect of treatment interventions would improve outcomes in these individuals, as it could help in the diagnosis of thromboembolic disease. Furthermore, this approach could streamline treatment strategies due to improved monitoring. A better understanding of hypercoagulability of HIV-infected patients is therefore urgently needed. In conclusion, the authors suggest a panel of pathology tests that should be considered as standard procedures when HIV is present.

Topics: Africa, Southern; Anti-HIV Agents; Blood Cell Count; Blood Coagulation Disorders; Blood Coagulation Tests; Fibrin; HIV Infections; Humans; Venous Thromboembolism; Venous Thrombosis

The physical properties of a venous thrombus are derived from molecular characteristics, including fibrin polymer diameter, density, branching, and cross-linking. Dense thrombi with thin, highly branched fibrin fibres and small pores in the meshwork have been observed to be more rigid, less permeable, and more resistant to lysis. The three dimensional fibrin meshwork acts as the main structure to entrap and capture erythrocytes, platelets and plasma components. Attached factors become integrated into the developing thrombus, co-localise with fibrin deposition and act in either a pro- or anticoagulant capacity. Similarly, factors including blood flow, osmolarity and pH, oxidative stress, platelet and leukocyte recruitment, and thrombin concentration alter thrombus composition, architecture, and its mechanical properties.. Over time, an increase in thrombus cellular composition and a linear decrease in fibrin content as a function of thrombus age is observed. However, little else is known regarding the evolution of fibrin based clots. The role of fibrin in mediating cellular coordination, thrombus maturation, and changes of the venous wall also requires further research. This review discusses the current impact of fibrin on thrombus remodeling and addresses the limitations of the work done in this area.

Topics: Animals; Blood Coagulation; Elasticity; Fibrin; Fibrinolysis; Humans; Protein Conformation; Structure-Activity Relationship; Time Factors; Vascular Remodeling; Veins; Venous Thrombosis; Viscosity

Prothrombotic fibrin clot phenotype, involving faster formation of dense meshwork composed of thinner and highly branched fibers that are relatively resistant to plasmin-induced lysis, has been reported in patients with not only myocardial infarction or stroke, but also venous thromboembolism (VTE), encompassing deep vein thrombosis (DVT), and/or pulmonary embolism (PE). Prothrombotic fibrin clot phenotype, in particular prolonged clot lysis time, is considered a novel risk factor for VTE as well as venous thrombosis at unusual location, for example, cerebral sinus venous thrombosis, retinal vein obstruction, and Budd-Chiari syndrome. Growing evidence from observational studies indicates that abnormal fibrin clot properties can predict recurrent DVT and PE and they are involved in serious complications of VTE, for example, thromboembolic pulmonary hypertension and postthrombotic syndrome. The purpose of this article is to review our current understanding of the role of fibrin clot structure and function in venous thrombosis with emphasis on clinical issues ranging from prognosis to therapy.

Topics: Fibrin; Humans; Pulmonary Embolism; Recurrence; Risk Factors; Venous Thrombosis

Arterial and venous thromboses are major contributors to coagulation-associated morbidity and mortality. Greater understanding of mechanisms leading to thrombus formation and stability is expected to lead to improved treatment strategies. Factor XIII (FXIII) is a transglutaminase found in plasma and platelets. During thrombosis, activated FXIII cross-links fibrin and promotes thrombus stability. Recent studies have provided new information about FXIII activity during coagulation and its effects on clot composition and function. These findings reveal newly-recognized roles for FXIII in thrombosis. Herein, we review published literature on FXIII biology and effects on fibrin structure and stability, epidemiologic data associating FXIII with thrombosis, and evidence from animal models indicating FXIII has an essential role in determining thrombus stability, composition, and size.

Topics: Animals; Blood Coagulation; Blood Platelets; Factor XIII; Fibrin; Humans; Transglutaminases; Venous Thrombosis

Cardiovascular disease is the leading cause of death and disability worldwide. Among cardiovascular causes of death, venous thrombosis (VT) is ranked third most common in the world. Venous thrombi have high red blood cell and fibrin content; however, the pathophysiologic mechanisms that contribute to venous thrombus composition and stability are still poorly understood. This article reviews biological, biochemical, and biophysical contributions of fibrinogen, factor XIII, and red blood cells to VT, and new evidence suggesting interactions between these components mediate venous thrombus composition and size.

Topics: Animals; Blood Coagulation; Erythrocytes; Factor XIII; Fibrin; Fibrinogen; Humans; Protein Conformation; Signal Transduction; Structure-Activity Relationship; Venous Thrombosis

Thrombotic events occurring in either arteries or veins are the primary causes of fatal perioperative cardiovascular events. Risk factors for deep vein thrombosis, several of which are evidently associated with specific surgical procedures, are quite different from those for arterial thrombosis (e.g., aging or atherosclerotic diseases). Thrombus formed in arteries consists mainly of platelets coated with fibrin (i.e., white thrombus), while venous thrombus formed at relatively lower shear stress consists of all blood components including erythrocytes as well as leukocytes infiltrated with fibrin (red thrombus). Clinical evidence indicates beneficial roles of neuraxial anesthesia/analgesia in the prevention of VTE for patients undergoing high risk surgical procedures. To date, mechanisms of action of drugs used for neuraxial anesthesia/analgesia to prevent venous thrombosis are uncertain. However, accumulation of clinical as well as experimental findings points to the involvement of immune cells (especially monocytes) in red thrombus generation and to the interaction of anesthetics with these cells. We also suggest that adhesion molecules associated with the formation of monocyte platelet aggregates as well as substance P: neurokinin-1 receptor (SP/NK1R) pathway that involves neurogenic inflammation are crucial. Local anesthetics and NK1R antagonists are candidate drugs that may possess the capability to prevent venous thrombotic disorders in perioperative settings.

Topics: Anesthetics, Local; Animals; Blood Platelets; Fibrin; Humans; Monocytes; Neurogenic Inflammation; Neurokinin-1 Receptor Antagonists; Receptors, Neurokinin-1; Risk Factors; Venous Thromboembolism; Venous Thrombosis

Fibrinogen is cleaved by thrombin to fibrin, which provides the blood clot with its essential structural backbone. As an acute phase protein, the plasma levels of fibrinogen are increased in response to inflammatory conditions. In addition to fibrinogen levels, fibrin clot structure is altered by a number of factors. These include thrombin levels, treatment with common cardiovascular medications, such as aspirin, anticoagulants, statins and fibrates, as well as metabolic disease states such as diabetes mellitus and hyperhomocysteinaemia. In vitro studies of fibrin clot structure can provide information regarding fibre density, clot porosity, the mechanical strength of fibres and fibrinolysis. A change in fibrin clot structure, to a denser clot with smaller pores which is more resistant to lysis, is strongly associated with cardiovascular disease. This pathological change is present in patients with arterial as well as venous diseases, and is also found in a moderate form in relatives of patients with cardiovascular disease. Pharmacological therapies, aimed at both the treatment and prophylaxis of cardiovascular disease, appear to result in positive changes to the fibrin clot structure. As such, therapies aimed at 'normalising' fibrin clot structure may be of benefit in the prevention and treatment of cardiovascular disease.

Topics: Arterial Occlusive Diseases; Blood Coagulation; Cardiovascular Agents; Cardiovascular Diseases; Fibrin; Fibrinogen; Fibrinolysin; Fibrinolysis; Humans; Porosity; Venous Thrombosis

Inherited antithrombin deficiency is estimated to carry a 50% risk of a venous thrombotic complication during each pregnancy and puerperium. We present a case of a female with heterozygous type I antithrombin deficiency who presented with a central nervous system transverse sinus thrombosis in the third trimester of pregnancy despite the use of therapeutic doses of low molecular weight heparin, as venous thromboembolic prophylaxis, since conception. A successful pregnancy outcome was achieved with the combined use of therapeutic anticoagulation and regular plasma-derived antithrombin concentrate infusions to normalize her antithrombin levels. This case lends further debate to the issue of whether antithrombin concentrate, in addition to anticoagulation, should be routinely administered for venous thromboembolic prophylaxis during pregnancy and the puerperium to women with inherited antithrombin deficiency. This point may become more relevant as further experience is gained with the use of recombinant human antithrombin.

Topics: Adult; Coagulation Protein Disorders; Female; Fibrin; Humans; Pregnancy; Pregnancy Complications, Hematologic; Sinus Thrombosis, Intracranial; Venous Thrombosis

Fibrin structure and stability have been linked to many thrombotic diseases, including venous thromboembolism. Analysis of the molecular mechanisms that affect fibrin structure and stability became possible when the crystal structure of fibrinogen was solved. Biochemical studies of natural and recombinant variant fibrinogens have examined the interactions that mediate the conversion of soluble fibrinogen to the insoluble fibrin network. These studies identified intermolecular interactions that control fibrin structure, although some critical events remain ambiguous. Studies show that fibrin structure modulates the enzymatic lysis of the fibrin network, so the molecular mechanisms that control structure also control stability. Studies show that the mechanical stability of the fibrin clot depends on the properties of the fibrin monomer, leading investigators to explore the molecular basis of the monomer's mechanical properties. The work summarized here provides insights that might allow the development of pharmaceuticals and treatments to modulate fibrin structure and stability in vivo and thereby prevent or limit thrombotic disease.

Topics: Animals; Blood Coagulation; Fibrin; Fibrinogen; Fibrinolysis; Fibrinolytic Agents; Humans; Protein Conformation; Structure-Activity Relationship; Venous Thrombosis

The D-dimer antigen is a unique marker of fibrin degradation that is formed by the sequential action of 3 enzymes: thrombin, factor XIIIa, and plasmin. First, thrombin cleaves fibrinogen producing fibrin monomers, which polymerize and serve as a template for factor XIIIa and plasmin formation. Second, thrombin activates plasma factor XIII bound to fibrin polymers to produce the active transglutaminase, factor XIIIa. Factor XIIIa catalyzes the formation of covalent bonds between D-domains in the polymerized fibrin. Finally, plasmin degrades the crosslinked fibrin to release fibrin degradation products and expose the D-dimer antigen. D-dimer antigen can exist on fibrin degradation products derived from soluble fibrin before its incorporation into a fibrin gel, or after the fibrin clot has been degraded by plasmin. The clinical utility of D-dimer measurement has been established in some scenarios, most notably for the exclusion of VTE. This article consists of 2 sections: in the first, the dynamics of D-dimer antigen formation is discussed and an overview of commercially available D-dimer assays is provided. The second section reviews available evidence for the clinical utilization of D-dimer antigen measurement in VTE, as well as emerging areas of D-dimer utilization as a marker of coagulation activation in other clinical settings.

Topics: Algorithms; Antibodies, Monoclonal; Clinical Laboratory Techniques; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Immunoassay; Models, Biological; Protein Structure, Tertiary; Pulmonary Embolism; Venous Thromboembolism; Venous Thrombosis

Fibrin-related markers (FRMs), such as fibrin and fibrinogen degradation products (FDPs), D-dimer, and soluble fibrin (SF), are considered to be useful for the diagnosis of thrombosis. However, the evidence for the making of a diagnosis of thrombosis based on FRMs is, as yet, not fully established. Levels of FRMs are significantly elevated in patients with thrombosis, such as deep vein thrombosis, disseminated intravascular coagulation, and so on. In Japan, the D-dimer assay test result might be 2-fold higher than results for those assays commonly used in Europe and North America. The levels of SF are significantly elevated in patients before the onset of thrombosis, thus suggesting that the SF assay is useful not only for the diagnosis of thrombosis but also for diagnosing a prethrombotic state. Overall, elevated levels of FRMs indicate a high risk for thrombosis, and they are thus considered to be useful for the diagnosis of thrombosis.

Topics: Biomarkers; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Risk Factors; Solubility; Thrombosis; Venous Thrombosis

The insertion and management of long-term venous catheters have long been the province of anaesthetists, intensive care physicians and surgeons. Radiologists are taking an increasing role in the insertion of central venous catheters (CVCs) because of their familiarity with the imaging equipment and their ability to manipulate catheters and guide-wires. The radiological management of the complications of CVCs has also expanded as a result. This article reviews the role of radiology in central venous access, covering the detection and management of their complications.

Topics: Aorta; Arteries; Catheterization, Central Venous; Fibrin; Foreign Bodies; Heart Injuries; Humans; Pneumothorax; Practice Guidelines as Topic; Pulmonary Artery; Radiology; Ultrasonography, Interventional; Venous Thrombosis

In rare cases of thromboembolic diseases developing in young age, venous and arterial thromboembolism can occur simultaneously.. To detect the venous and the arterial risk factors in a severe thrombophilic family. A 47-years-old female with severe atherosclerosis and recurrent deep vein thrombosis, and 6 members of her family were analysed.. The following haemostatic and molecular genetic investigations were performed: besides the rutin haemostatic parameters, risk factors for venous thrombembolic disease, risk factors for venous and arterial thrombosis (plasma homocysteine level, MTHFR C677T polymorphism) were determined. This panel was completed with the measurement of lipoprotein (a), von Willebrand factor, plasminogen activator inhibitor-1 antigen, serum total cholesterin, HDL cholesterin, C reactive protein and PIA2 variant. The propositus was proven to have type I antithrombin deficiency, elevated homocysteine level, homozygous MTHFR C677T polymorphism, elevated Lp(a), vWF:Ag, and PAI-1:Ag levels.. All family members had a combination of cardiovascular risk factors (in 4 cases elevated homocysteine level, in 3 cases elevated Lp(a), in 2 cases elevated vWF:Ag, in 4 cases increased PAI-1 level). These risk factors were combined in three cases with type I antithrombin deficiency. Despite of the presence of atherosclerotic risk factors in the family, arterial thrombotic disease could be detected only in two patients with antithrombin deficiency.. The results of the investigated family indicate that in case of combination of venous and arterial thromboembolic risk factors, antithrombin deficiency may contribute to the manifestation of arterial thromboembolic diseases.

Topics: Adult; C-Reactive Protein; Cholesterol; Cysteine; Female; Fibrin; Genetic Predisposition to Disease; Homocysteine; Humans; Male; Pedigree; Plasminogen Activator Inhibitor 1; Polymorphism, Genetic; Risk Factors; Threonine; Thrombophilia; Thrombosis; Venous Thrombosis; von Willebrand Factor

Central venous catheter malfunction diagnosis and treatment is a growing component of the field of interventional radiology. A thorough understanding of the causes of catheter malfunction and the technical skills needed to treat these problems are necessities to appropriate management. In long-standing central venous catheters, the formation of a fibrin sheath can and often does contribute to catheter malfunction. Differentiating a sheath from thrombus is imperative to appropriate therapy. The purpose of this article is to provide an understanding of the causes of fibrin sheaths and how to treat them.

Topics: Catheterization, Central Venous; Catheters, Indwelling; Diagnosis, Differential; Equipment Failure; Fibrin; Fibrinolytic Agents; Humans; Thrombolytic Therapy; Venous Thrombosis

Soluble fibrin detected in clinical plasma samples includes a variety of complexes consisting of fibrin monomer units, fibrinogen, and various proteolytic derivatives of fibrinogen and fibrin. The advantage of measuring soluble fibrin over fibrinopeptide A to detect thrombin action on fibrinogen is the considerably longer half-life of soluble fibrin in the circulation. Soluble fibrin can be detected by a variety of methods, including paracoagulation and precipitation assays, adsorption of fibrin monomer to insolubilized fibrinogen, functional assays based on the cofactor activity of some soluble fibrin compounds in t-PA-induced plasminogen activation, and by using fibrin-specific antibodies. Fibrin-specific antibodies may react with epitopes generated directly by fibrinopeptide A or B release or with epitopes generated by fibrin polymerization. Epitopes dependent on fibrinopeptide A release are often not accessible in native fibrin complexes and require the disaggregation of fibrin compounds to be reactive, whereas epitopes dependent on fibrinopeptide B release or fibrin polymerization are accessible to the monoclonal antibodies in nondenatured fibrin. Since soluble fibrin assays detect different structural or functional properties of soluble fibrin, no common calibrator for all soluble fibrin assays and, often, little correlation between different assay systems in clinical evaluations exist. Clinical applications of soluble fibrin assays include diagnosis and treatment monitoring of intravascular coagulation processes and prethrombotic states, monitoring anticoagulant treatment, and biocompatibility investigations. Some soluble fibrin assays have been demonstrated to be extremely sensitive indicators of acute fibrin formation. For the exclusion of venous thrombosis, D-dimer assays appear to be more sensitive than current soluble fibrin assays, since D-dimer assays detect freshly formed fibrin and proteolytic fragments of particulate clots. Further clinical studies are needed to establish the clinical utility of specific, soluble fibrin assays. The development of rapid, quantitative soluble fibrin assays for clinical routine use should be encouraged.

Topics: Acute Disease; Animals; Blood Coagulation; Chronic Disease; Disseminated Intravascular Coagulation; Epitopes; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Plasminogen; Thrombophilia; Venous Thrombosis

We evaluated hemostatic markers in patients who underwent major orthopedic surgery, including total hip and total knee arthroplasty, and were treated for the prophylaxis of deep vein thrombosis (DVT) with or without fondaparinux (anti-Xa group, n = 98 and without anti-Xa group, n = 20). The frequency of DVT was significantly higher in the without anti-Xa group than in the anti-Xa group, but the reduction of hemoglobin and fibrinolytic marker levels was significantly lower in the without anti-Xa group than in the anti-Xa group. Eighteen patients in the anti-Xa group showed a reduction in hemoglobin of more than 2 g/dl, and those individuals were considered to be the increased bleeding (IB) group. The concentration of fibrinolytic markers in the anti-Xa group was significantly higher in the IB group than in the non-IB group. There were also no significant differences in the levels of anti-Xa activity, plasminogen activator inhibitor-I, soluble fibrin and antithrombin between the IB and non-IB groups. In conclusion, elevated fibrinolysis induced by increased bleeding may lead to further increases in bleeding in patients receiving thromboprophylaxis with fondaparinux following major orthopedic surgery.

Topics: Aged; Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Biomarkers; Factor Xa Inhibitors; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinolysis; Fondaparinux; Hemorrhage; Humans; Male; Middle Aged; Polysaccharides; Postoperative Complications; Venous Thrombosis

(99m)Tc-DI-DD3B6/22-80B3 (ThromboView, hereafter abbreviated to (99m)Tc-DI-80B3 Fab') is a radiolabelled humanised monoclonal Fab' fragment with affinity and specificity for D-dimer domains of cross-linked fibrin. Detection of thromboembolic events has been demonstrated in canine models. The study objectives were evaluation of safety and characterisation of biodistribution, immunogenicity and pharmacokinetic profile of increasing doses of (99m)Tc-DI-80B3 Fab' in subjects with acute lower-limb DVT.. Twenty-six patients with acute lower limb DVT were enrolled. Of these, 21 received a single intravenous dose of 0.5 mg (n = 6), 1.0 mg (n = 9) or 2 mg (n = 6) (99m)Tc-DI-80B3 Fab'. Blood and urine samples and gamma camera images were collected to 24 h after administration for pharmacokinetic and dosimetry analysis. Vital signs, electrocardiography, hematological and biochemical data and human anti-human antibody (HAHA) levels were monitored for up to 30 days following administration. Patients were assigned to either planar or single photon emission computed tomographic (SPECT) imaging of the thorax at 4 h following injection.. Thirty-five adverse events were reported in 15 of the 21 subjects. Those deemed possibly related to administration of (99m)Tc-DI-80B3 Fab' included mild hypertension, mild elevation of LD (lactate dehydrogenase) and moderate elevation of ALT (alanine transaminase). HAHA assays remained negative. Pharmacokinetics and organ dosimetry were comparable to prior normal volunteer data. Localisation of Thromboview to sites of known thrombus was evident as early as 30 min post-injection.. In subjects with acute DVT, (99m)Tc-DI-80B3 Fab' was well tolerated with favourable characteristics for the detection of acute venous thrombosis.

Topics: Adult; Aged; Female; Fibrin; Humans; Image Processing, Computer-Assisted; Immunoglobulin Fab Fragments; Injections, Intravenous; Male; Middle Aged; Organotechnetium Compounds; Protein Multimerization; Protein Structure, Quaternary; Radiometry; Safety; Staining and Labeling; Tissue Distribution; Tomography, Emission-Computed, Single-Photon; Venous Thrombosis

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Predictive Value of Tests; Pulmonary Embolism; Sensitivity and Specificity; Upper Extremity; Venous Thrombosis

To assess the influence of a variety of HRT regimens on the haemostatic balance using markers of fibrin turnover and inhibitors of coagulation.. An open randomised study allocating women to either a control group or five different HRT treatment groups.. Gentofte Hospital, Hellerup, and Rigshospitalet, Copenhagen, Denmark.. One hundred and forty-nine postmenopausal women without previous venous thromboembolic disease.. Prothrombin fragment 1+2 (F(1+2)), fibrin degradation products, antithrombin, protein C, total protein S and activated protein C-normalised ratio were measured at baseline and after 6 and 12 months of HRT in six groups of healthy postmenopausal women: (A). no HRT (reference group), (B). continuous oestradiol valerate (E(2)V) plus cyproterone acetate, (C). cyclic E(2)V plus cyproterone acetate, (D). continuous combined oestrogen (E(2)) plus norethindrone acetate, (E). E(2) combined with local delivery of levonorgestrel and (F). E(2)V plus medroxyprogesterone. HRT-induced changes in the concentration of inhibitors of coagulation and markers of fibrin turnover during 12 months of treatment.. Significant decreases of antithrombin and protein S were found in all treatment groups, of protein C in Groups C, D, E and F and of activated protein C-normalised ratio in Groups E and F. Fibrin degradation products increased after three months of treatment, whereas F(1+2) was persistently increased after three months in Group F. The cumulative response of antithrombin was significantly lower in Groups D, E and F than in the reference group. The cumulative response of protein S and activated protein C-normalised ratio was lower, whereas that of F(1+2) was significantly higher in Group F than in the reference group.. HRT reduces the inhibitory potential of coagulation significantly. The effect is related to the type of E(2)/progestin combination administered, but seems to be oestrogen-derived as the most pronounced effect is found with only quarterly progestin intake. Such procoagulant activity of HRT may well translate into clinical manifestations in thrombosis-prone individuals.

Topics: Adult; Estrogen Replacement Therapy; Female; Fibrin; Humans; Middle Aged; Peptide Fragments; Postmenopause; Prospective Studies; Protein C; Protein S; Prothrombin; Risk Factors; Thromboembolism; Venous Thrombosis

The role of blood tests in identifying patients at high risk for post-operative venous thromboembolism is undefined. The aim of this study was to evaluate the correlation between pre-operative plasma levels of soluble fibrin polymers (SFP), as determined by a recently developed enzyme-linked immunosorbent assay (ELISA) assay (TpP), and the incidence of deep vein thrombosis (DVT) after elective neurosurgery. Blood samples for SFP assay were withdrawn on the day before surgery from 157 consecutive patients undergoing elective neurosurgery for brain or spinal tumour. Patients were randomized to subcutaneous enoxaparin (40 mg once daily) or placebo given for at least 7 days. All patients wore compression stockings. DVT was assessed by bilateral venography, performed on day 8 +/- 1. Thirty-four patients (21.7%) were found to have a DVT, proximal in 11 (7%) and isolated distal in 23. Patients with and without DVT had a plasma pre-operative SFP levels of 6.2 +/- 4.6 and 1.9 +/- 1.5 mg/ml respectively (mean +/- SD) (P < 0.001). SFP levels in patients with proximal and isolated distal DVT were 7.6 +/- 5.1 and 5.5 +/- 4.4 microg/ml, respectively (P = 0.22). SFP cut-off levels categorized patients into three classes of DVT incidence. The incidence of DVT was 7.4% (6 of 81) for SFP levels < 2 microg/ml, 20.4% (11 of 54) for levels between 2 and 4.5 microg/ml, and 77.3% (17 of 22) for levels > 4.5 microg/ml (P= 0.001, Cochran-Mantel-Haenszel test). We conclude that pre-operative SFP levels correlate with post-operative DVT in elective neurosurgery patients. Further studies are required to define whether pre-operative SFP measurement could be useful in patient management.

Topics: Adult; Aged; Biomarkers; Brain Neoplasms; Elective Surgical Procedures; Enoxaparin; Female; Fibrin; Humans; Italy; Male; Middle Aged; Neurosurgical Procedures; Risk Factors; Solubility; Spinal Neoplasms; Venous Thrombosis

Thrombus are blood clots formed by abnormal hemostasis in blood vessels and are closely associated with various diseases such as pulmonary embolism, myocardial infarction and stroke. Early diagnosis and treatment of thrombus is the key to reducing the high risk of thrombotic disease. Given that early thrombus is small in early size, free instability, wide regional distribution and fast formation, it is urgent to develop all-inclusive detection methods that combine high signal-to-noise ratio, in situ dynamic and rapid in-depth tissue imaging. Near-infrared (NIR) fluorescence imaging, with its excellent high spatiotemporal resolution and tissue penetration depth, is a powerful technique for direct visualization of thrombotic events in situ. Considering the fibrin highly expressed in the thrombus is a typical thrombotic target. Moreover, the viscosity of the thrombus is markedly higher than its surroundings. Therefore, we developed a fibrin-targeting and viscosity-activating thrombus NIR fluorescent probe (TIR-V) for high-resolution and high-sensitivity in situ lighten-up thrombus. TIR-V has the advantages of good thrombus targeting, significant "off-on" fluorescence specific response to viscosity, bright NIR fluorescence and good biocompatibility. The thrombus is clearly delineated by a high signal-to-noise ratio NIR fluorescence imaging, enabling imaging detection and precise navigation of thrombotic regions. This work demonstrates the potential of TIR-V as a bifunctional probe for definitive diagnostic imaging and direct navigation of thrombotic lesions in clinical applications.

Topics: Fibrin; Fluorescence; Fluorescent Dyes; Humans; Optical Imaging; Thrombosis; Venous Thrombosis; Viscosity

 Catheter-directed thrombolysis (CDT) is an effective therapy for acute deep vein thrombosis (DVT). However, predicting the CDT outcomes remains elusive. We hypothesized that the thrombus signal on T1-weighted black-blood magnetic resonance (MR) can provide insight into CDT outcomes in acute DVT patients..  A total of 117 patients with acute iliofemoral DVT were enrolled for T1-weighted black-blood MR before CDT in this prospective study. Based on the signal contrast between thrombus and adjacent muscle, patients were categorized into the iso-intense thrombus (Iso-IT), hyper-intense thrombus (Hyper-IT), and mixed iso-/hyper-intense thrombi (Mixed-IT) groups. Immediate treatment outcome (i.e., vein patency) and long-term treatment outcome (i.e., the incidence rate of postthrombotic syndrome) were accessed by the same expert. Histological analysis and iron quantification were performed on thrombus samples to characterize the content of fibrin, collagen, and the ratio of Fe.  Compared to Mixed-IT and Hyper-IT groups, the Iso-IT group had the best lytic effect (90.5 ± 1.6% vs. 78.4 ± 2.6% vs. 46.5 ± 3.3%,.  Thrombus signal characteristics on T1-weighted black-blood MR is associated with CDT outcomes and possesses potential to serve as a noninvasive approach to guide treatment decision making in acute DVT patients.. · Thrombus signal on T1-weighted black-blood MR is associated with lytic therapeutic outcome in acute DVT patients.. · Presence of iso-intense thrombus revealed by T1-weighted black-blood MRI is associated with successful thrombolysis, low bleeding ratio, and low incidence of the postthrombotic syndrome.. · T1-weighted thrombus signal characteristics may serve as a noninvasive imaging marker to predict CDT treatment outcomes and therefore guide treatment decision making in acute DVT patients..

Topics: Catheters; Femoral Vein; Fibrin; Hemorrhage; Humans; Iliac Vein; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Postphlebitic Syndrome; Postthrombotic Syndrome; Prospective Studies; Retrospective Studies; Thrombolytic Therapy; Treatment Outcome; Venous Thrombosis

Portal vein thrombosis (PVT) is a common complication of cirrhosis. The exact pathophysiology remains largely unknown, and treatment with anticoagulants does not lead to recanalization of the portal vein in all patients. A better insight into the structure and composition of portal vein thrombi may assist in developing strategies for the prevention and treatment of PVT.. Sixteen prospectively and 63 retrospectively collected nonmalignant portal vein thrombi from patients with cirrhosis who underwent liver transplantation were included. Histology, immunohistochemistry, and scanning electron microscopy were used to assess structure and composition of the thrombi. Most recent CT scans were reanalyzed for thrombus characteristics. Clinical characteristics were related to histological and radiological findings. All samples showed a thickened, fibrotic tunica intima. Fibrin-rich thrombi were present on top of the fibrotic intima in 9/16 prospective cases and in 21/63 retrospective cases. A minority of the fibrotic areas stained focally positive for fibrin/fibrinogen (16% of cases), von Willebrand factor (VWF; 10%), and CD61 (platelets, 21%), while most of the fibrin-rich areas stained positive for those markers (fibrin/fibrinogen, 100%; VWF, 77%; CD61, 100%). No associations were found between clinical characteristics including estimated thrombus age and use of anticoagulants and presence of fibrin-rich thrombi.. We demonstrate that PVT in patients with cirrhosis consists of intimal fibrosis with an additional fibrin-rich thrombus in only one-third of cases. We hypothesize that our observations may explain why not all portal vein thrombi in patients with cirrhosis recanalize by anticoagulant therapy.

Topics: Anticoagulants; Fibrin; Fibrinogen; Humans; Liver Cirrhosis; Portal Vein; Retrospective Studies; Thrombosis; Venous Thrombosis; von Willebrand Factor

Lower extremity deep venous thrombosis (LEDVT) is a venous reflux disorder caused by abnormal coagulation of blood. LEDVT can obstruct the lumen and LEDVT is the third vascular disease after cerebrovascular diseases and coronary artery diseases. miRNAs are associated with thrombosis, and miR-185 was reported to affect the proliferation and apoptosis of vascular endothelial cells by regulating receptor of advanced glycation end products (RAGE). However, no study has reported the effect of miR-185 on LEDVT. Here, we studied the effects of miR-185 on the PI3K/AKT and MAPK signaling pathways in the LEDVT cells. The results showed that miR-185 promotes cell proliferation through activating the PI3K/AKT and MAPK signaling pathways and then inhibits tissue factor and fibrin expression to reduce thrombosis. In short, our study provides new ideas and a theoretical basis for research on the prevention, diagnosis, and treatment of LEDVT.

Topics: Animals; Cell Proliferation; Cells, Cultured; Chromones; Disease Models, Animal; Endothelial Cells; Fibrin; Male; MAP Kinase Signaling System; Mice; MicroRNAs; Morpholines; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats; Thromboplastin; Venous Thrombosis

Formation of intravenous catheter-related thrombosis leads to central venous stenosis in patients requiring renal replacement therapy or chemotherapy infusion, yet the triggers or mechanisms remain unclear, especially in patients without symptoms of infection. In this study, we found that neutrophil extracellular traps (NETs) could be detected in the fibrin sheaths from dialysis patients without clinical manifestations of infection. Confocal microscopy revealed bacteria imbedded in NETs in the fibrin sheaths. Thirty-nine of 50 (78%) fibrin sheath specimens contained bacteria detectable by 16S ribosomal RNA genome typing with a predominance of

Topics: Animals; Bacteremia; Catheters, Indwelling; Constriction, Pathologic; Extracellular Traps; Fibrin; Neutrophils; Rats; Staphylococcus aureus; Thrombosis; Venous Thrombosis

Pulmonary embolism is a life-threatening condition, which can result in respiratory insufficiency and death. Blood clots occluding branches of the pulmonary artery (PA) are traditionally considered to originate from thrombi in deep veins (usually in legs). However, growing evidence suggests that occlusion of the vessels in the lungs can develop without preceding deep vein thrombosis (DVT). In this work, we used an inferior vena cava (IVC) complete ligation model of DVT in Wistar rats to explore the possibility and mechanisms of PA thrombosis under the conditions where all routes of thrombotic mass migration from peripheral veins are blocked. We demonstrate that rats both with normal and reduced neutrophil counts developed thrombi in the IVC, although, neutropenia caused a substantial decrease in thrombus size and a shift from fresh fibrin toward mature fibrin and connective tissue inside the thrombus. Massive fibrin deposition was found in the PA branches in the majority of DVT rats with normal neutrophil counts, but in none of the neutropenic animals. Neutrophil ablation also abolished macroscopic signs of lung damage. Altogether, the results demonstrate that thrombi in the lung vasculature can form in situ by mechanisms that require local neutrophil recruitment taking place in the DVT setting.

Topics: Animals; Fibrin; Lung; Neutrophils; Pulmonary Artery; Rats; Rats, Wistar; Venous Thrombosis

The efficacy of thrombolysis is inversely correlated with thrombus age. During early thrombogenesis, activated factor XIII (FXIIIa) cross-links α2-AP to fibrin to protect it from early lysis. This was exploited to develop an α2-AP-based imaging agent to detect early clot formation likely susceptible to thrombolysis treatment. In this study, this imaging probe was improved and validated using 111In SPECT/CT in a mouse thrombosis model. In vitro fluorescent- and 111In-labelled imaging probe-to-fibrin cross-linking assays were performed. Thrombus formation was induced in C57Bl/6 mice by endothelial damage (FeCl3) or by ligation (stenosis) of the infrarenal vena cava (IVC). Two or six hours post-surgery, mice were injected with 111In-DTPA-A16 and ExiTron Nano 12000, and binding of the imaging tracer to thrombi was assessed by SPECT/CT. Subsequently, ex vivo IVCs were subjected to autoradiography and histochemical analysis for platelets and fibrin. Efficient in vitro cross-linking of A16 imaging probe to fibrin was obtained. In vivo IVC thrombosis models yielded stable platelet-rich thrombi with FeCl3 and fibrin and red cell-rich thrombi with stenosis. In the stenosis model, clot formation in the

Topics: Animals; Constriction, Pathologic; Disease Models, Animal; Fibrin; Mice; Mice, Inbred C57BL; Thrombosis; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Venous Thrombosis

Fibrinolysis is of paramount importance in maintaining or regaining the patency of veins and pulmonary arteries obstructed by thrombi. Growing experimental and clinical evidence indicates that impaired fibrinolysis mediated by multiple complex mechanisms is involved in venous thromboembolism (VTE). Global plasma fibrin clot lysis markers, especially clot lysis time, have been reported to predict recurrent deep-vein thrombosis and pulmonary embolism. The current overview summarizes available data linking fibrinolysis to VTE and its long-term sequelae.

Topics: Fibrin; Fibrin Clot Lysis Time; Fibrinolysis; Humans; Venous Thromboembolism; Venous Thrombosis

Although arterial and venous thromboembolic disorders are among the most frequent causes of mortality and morbidity, there has been little description of how the composition of thrombi and emboli depends on their vascular origin and age. We quantified the structure and composition of arterial and venous thrombi and pulmonary emboli using high-resolution scanning electron microscopy. Arterial thrombi contained a surprisingly large amount of fibrin, in addition to platelets. The composition of pulmonary emboli mirrored the most distal part of venous thrombi from which they originated, which differed from the structure of the body and head of the same thrombi. All thrombi and emboli contained few biconcave red blood cells but many polyhedrocytes or related forms of compressed red blood cells, demonstrating that these structures are a signature of clot contraction in vivo. Polyhedrocytes and intermediate forms comprised the major constituents of venous thrombi and pulmonary emboli. The structures within all of the thrombi and emboli were very tightly packed, in contrast to clots formed in vitro. There are distinctive, reproducible differences among arterial and venous thrombi and emboli related to their origin, destination and duration, which may have clinical implications for the understanding and treatment of thrombotic disorders.

Topics: Arteries; Blood Coagulation; Blood Platelets; Erythrocytes; Fibrin; Humans; Microscopy, Electron, Scanning; Pulmonary Embolism; Thromboembolism; Veins; Venous Thrombosis

The intrinsic pathway factors (F) XII and FXI have been shown to contribute to thrombosis in animal models. We assessed the role of FXII and FXI in venous thrombosis in three distinct mouse models.. Venous thrombosis was assessed in mice genetically deficient for either FXII or FXI. Three models were used: the inferior vena cava (IVC) stasis, IVC stenosis, and femoral vein electrolytic injury models.. In the IVC stasis model, FXII and FXI deficiency did not affect the size of thrombi but their absence was associated with decreased levels of fibrin(ogen) and an increased level of the neutrophil extracellular trap marker citrullinated histone H3. In contrast, a deficiency of either FXII or FXI resulted in a significant and equivalent reduction in thrombus weight and incidence of thrombus formation in the IVC stenosis model. Thrombi formed in the IVC stenosis model contained significantly higher levels of citrullinated histone H3 compared with the thrombi formed in the IVC stasis model. Deletion of either FXII or FXI also resulted in a significant and equivalent reduction in both fibrin and platelet accumulation in the femoral vein electrolytic injury model.. Collectively, these data indicate that FXII and FXI contribute to the size of venous thrombosis in models with blood flow and thrombus composition in a stasis model. This study also demonstrates the importance of using multiple mouse models to assess the role of a given protein in venous thrombosis.

Topics: Animals; Disease Models, Animal; Factor XI; Factor XII; Fibrin; Mice; Thrombosis; Venous Thrombosis

Venous ulcers are the most severe manifestation of post-thrombotic syndrome (PTS). We have previously demonstrated that formation of compact fibrin clots resistant to lysis is observed in patients following deep-vein thrombosis (DVT) who developed PTS. The current study investigated whether unfavourable fibrin clot properties can predict post-thrombotic venous ulcers. In a cohort study on 186 consecutive patients following DVT, we determined plasma fibrin clot characteristics, including clot permeability and lysability, inflammatory markers, thrombin generation, fibrinolysis proteins at 3 months since the index event. Occurrence of PTS and venous ulcers was recorded during follow-up (median, 53; range 24 to 76 months). Fifty-seven DVT patients (30.6%) developed PTS, including 12 subjects (6.45%) with a venous ulcer (4 individuals with recurrent ulcers). Patients who developed ulcers compared with the remainder had at enrolment 13.0% lower clot permeability (K

Topics: Adult; alpha-2-Antiplasmin; Body Mass Index; Cohort Studies; Female; Fibrin; Fibrin Clot Lysis Time; Humans; Male; Middle Aged; Postthrombotic Syndrome; Risk Factors; Varicose Ulcer; Venous Thrombosis

Central vascular access device (CVAD)-related sheaths, sometimes described as 'fibrin sheaths', may result in minor or significant sequelae, from persistent withdrawal occlusion (PWO) to infective sheaths associated with increased morbidity and mortality. The authors studied 179 patients who underwent isotope scans, where isotope was infused via the CVAD. Isotope was found to bind to the sheaths around the catheters of some patients. The amount of uptake was taken to be an extent to which a sheath had developed around the CVAD. The degree of uptake of isotope was categorised into three groups: low uptake, moderate uptake and high uptake. Patients were then followed up from the date the CVAD was inserted to 12 months after the date of the isotope scan, until the device was removed or to the date the patient died, to identify incidence of infection, thrombosis and PWO. PWO incidence in all levels of uptake was around 5-7%. Bloodstream infection (BSI) incidence for low uptake was 7% (9/130), moderate uptake 10% (3/30) and for patients with significant uptake 16% (3/19). Thrombosis for no uptake was less than 1% (1/130), moderate uptake 7% (2/30), and significant uptake had no incidence of thrombosis. Total complications: no uptake 15%, moderate uptake 23% and significant uptake 21%. This single-centre study showed that patients with isotope-highlighted sheaths experienced higher incidence of infective, thrombotic and total complications.

Topics: Catheter-Related Infections; Central Venous Catheters; Fibrin; Humans; Incidence; Venous Thrombosis

The cutoff values of D-dimer levels for diagnosing or predicting the occurrence of deep vein thrombosis (DVT) were evaluated in preoperative patients and compared to those in non-DVT patients. The levels of 8 different D-dimers were measured using the latex agglutination method or enzyme immunoassay before surgery in 262 orthopedic surgery patients to diagnose subclinical DVT or predict postoperative DVT. There were 15 patients with subclinical DVT and 47 with postoperative DVT, but 200 patients had no DVT at all. All 8 plasma D-dimer values were significantly higher in the patients with subclinical or postoperative DVT than in those without DVT or in healthy volunteers. There were differences in the cutoff values between the assays highly sensitive for low D-dimer levels and wild-range assays of D-dimers. Some D-dimer assays might therefore be more useful than others for diagnosing low levels of D-dimer. Although the measurement of D-dimer levels was useful for diagnosing subclinical DVT and predicting the risk of DVT, the cutoff values for the diagnosis or prediction of DVT varied. The cutoff values for the prediction of postoperative DVT were ≥1.7 µg/mL (D-dimer A-D) and ≥1.0 µg/mL (D-dimer E-H).

Topics: Aged; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Male; Middle Aged; Pulmonary Embolism; Venous Thrombosis

The transglutaminase factor XIII (FXIII) stabilizes clots against mechanical and biochemical disruption and is essential for hemostasis. In vitro and in vivo models of venous thrombosis demonstrate that FXIII mediates clot size by promoting red blood cell (RBC) retention. However, the key source of FXIII and whether FXIII activity can be reduced to suppress thrombosis without imposing deleterious hemostatic consequences are 2 critical unresolved questions. FXIII is present in multiple compartments, including plasma (FXIII

Topics: Animals; Blood Platelets; Erythrocytes; Factor XIII; Fibrin; Hemorrhage; Mice; Plasma; Thrombin; Thrombosis; Venous Thrombosis

Pulmonary thromboembolic events cause significant morbidity and mortality after severe trauma. Clinically, these lesions are believed to be emboli arising secondary to deep venous thrombosis (DVT) in the lower extremities. Recently, this notion has been challenged by clinical studies, showing that pulmonary clots arise after trauma in the absence of DVT. This suggests that pulmonary blood clots arise in situ via de novo thrombosis. In the present study, we characterize a murine weight-drop model of lateral blunt thoracic trauma. Our model demonstrates severe unilateral lung contusion injury with low (10%) mortality in the absence of extrapulmonary injury, after impact with a 50-g weight dropped from 45 cm height (657 J/m). At 24 h after injury, immunofluorescence and histological evidence revealed early pulmonary arterial thrombosis in the form of eccentric accumulation of fibrin and CD41 positive eosinophilic proteinaceous material, on both coup and contrecoup lung lobes of injured mice, indicating early thrombotic events both within and outside of the area of primary lung injury. Our model is ideal in that lateral impact enables greater impact energy to be applied to achieve significant lung contusion without significant mortality or extrapulmonary injury, and the model has additional translational value in creating thrombosis analogous to pulmonary embolism observed clinically after blunt thoracic trauma. To our knowledge, this is the first demonstration of de novo pulmonary thrombosis in a clinically translational model of blunt thoracic trauma, and supports challenges to current assumptions about the origin of pulmonary blood clots in the wake of severe traumatic injury.

Topics: Animals; Bronchoalveolar Lavage; Disease Models, Animal; Fibrin; Fluorescent Antibody Technique; In Situ Nick-End Labeling; Male; Mice; Mice, Inbred C57BL; Platelet Membrane Glycoprotein IIb; Pulmonary Embolism; Thoracic Injuries; Venous Thrombosis

The objective of this study was to measure the role of platelets and red blood cells on thrombus propagation in an in vitro model of venous valvular stasis.. A microfluidic model with dimensional similarity to human venous valves consists of a sinus distal to a sudden expansion, where for sufficiently high Reynolds numbers, 2 countercurrent vortices arise because of flow separation. The primary vortex is defined by the points of flow separation and reattachment. A secondary vortex forms in the deepest recess of the valve pocket characterized by low shear rates. An initial fibrin gel formed within the secondary vortex of a tissue factor-coated valve sinus. Platelets accumulated at the interface of the fibrin gel and the primary vortex. Red blood cells at physiological hematocrits were necessary to provide an adequate flux of platelets to support thrombus growth out of the valve sinus. A subpopulation of platelets that adhered to fibrin expose phosphatidylserine. Platelet-dependent thrombus growth was attenuated by inhibition of glycoprotein VI with a blocking Fab fragment or D-dimer.. A 3-step process regulated by hemodynamics was necessary for robust thrombus propagation: First, immobilized tissue factor initiates coagulation and fibrin deposition within a low flow niche defined by a secondary vortex in the pocket of a model venous valve. Second, a primary vortex delivers platelets to the fibrin interface in a red blood cell-dependent manner. Third, platelets adhere to fibrin, activate through glycoprotein VI, express phosphatidylserine, and subsequently promote thrombus growth beyond the valve sinus and into the bulk flow.

Topics: Blood Coagulation; Blood Flow Velocity; Blood Platelets; Erythrocytes; Fibrin; Hematocrit; Hemodynamics; Humans; Lab-On-A-Chip Devices; Microfluidic Analytical Techniques; Phosphatidylserines; Platelet Membrane Glycoproteins; Signal Transduction; Stress, Mechanical; Thromboplastin; Venous Thrombosis; Venous Valves

Prothrombotic clot phenotype may characterize patients developing deep vein thrombosis (DVT) despite pharmacological thromboprophylaxis. We studied the role of fibrin clot properties and its potential determinants in individuals who experienced DVT after lower limb injury.. In a case-control study, we assessed 50 patients who developed DVT despite prophylactic use of low-molecular-weight heparins (the failed thromboprophylaxis group) after a lower limb injury, and three age- and sex-matched control groups, 50 patients each: (1) patients with trauma-related DVT without prior thromboprophylaxis; (2) individuals with unprovoked DVT; (3) patients without history of DVT (the no-DVT controls). Fibrin clot properties, along with thrombin concentration and α. Patients who experienced DVT despite thromboprophylaxis following lower limb trauma display a strongly prothrombotic fibrin clot phenotype, including increased clot density and hypofibrinolysis associated with higher plasma α

Topics: Adult; alpha-2-Antiplasmin; Anticoagulants; Blood Coagulation; Case-Control Studies; Female; Fibrin; Fibrin Clot Lysis Time; Fibrinolysis; Genotype; Heparin, Low-Molecular-Weight; Humans; Lower Extremity; Male; Middle Aged; Odds Ratio; Permeability; Phenotype; Poland; Thrombin; Thrombosis; Ultrasonography, Doppler; Venous Thromboembolism; Venous Thrombosis; Wounds and Injuries

Pyriform fossa sinus tracts classically present with neck abscess, recurrent infections and suppurative thyroiditis in children; acute presentation in a geriatric patient is rare.. Case report and Medline literature review.. A 79-year-old female presented with a left-sided neck mass and severe odynophagia of 3 days' duration. Magnetic resonance imaging revealed a large-volume, loculated fluid collection extending throughout the deep spaces of the neck on the left, within and around the thyroid gland capsule. There was radiological evidence of internal jugular vein thrombophlebitis. Abscess incision and drainage, and endoscopic evaluation, were performed. A deeply penetrating sinus was seen in the left pyriform apex, the entrance of which was circumferentially cauterised and the lumen obliterated with fibrin glue. Following post-operative intravenous antibiotics, the patient made a complete recovery.. This paper describes the first use of fibrin glue to obliterate a pyriform fossa sinus tract in an adult.

Topics: Aged; Electrocoagulation; Endoscopy; Female; Fibrin; Humans; Jugular Veins; Magnetic Resonance Imaging; Pyriform Sinus; Retrospective Studies; Treatment Outcome; Venous Thrombosis

Plasminogen (Plg) is a precursor of plasmin that degrades fibrin. A race-specific A620T mutation in Plg, also known as Plg-Tochigi, originally identified in a patient with recurrent venous thromboembolism, causes dysplasminogenemia with reduced plasmin activity. The Plg-A620T mutation is present in 3-4% of individuals in East Asian populations, and as many as 50,000 Japanese are estimated to be homozygous for the mutant 620T allele. In the present study, to understand the changes of thrombotic phenotypes in individuals with the mutant 620T allele, we generated knock-in mice carrying the homozygous Plg-A622T mutation (PlgT/T), an equivalent to the A620T mutation in human Plg. PlgT/T mice grew normally but showed severely reduced plasmin activity activated by urokinase, equivalent to ~8% of that in wild-type mice. In vitro fibrin clot lysis in plasma was significantly slower in PlgT/T mice than in wild-type mice. However, all experimental models of electrolytic deep vein thrombosis, tissue factor-induced pulmonary embolism, transient focal brain ischaemic stroke, or skin-wound healing showed largely similar phenotypes between PlgT/T mice and wild-type mice. Protein S-K196E mutation (Pros1E/E) is a race-specific genetic risk factor for venous thromboembolism. Coexistence in mice of PlgT/T and Pros1E/E did not affect pulmonary embolism symptoms, compared with those in Pros1E/E mice. Hence, the present study showed that the Plg-A622T mutation, which confers ~8% plasmin activity, does not increase the risk of thrombotic diseases in mice under experimental thrombotic conditions and does not modify the thrombotic phenotype observed in Pros1E/E mice. PlgT/T mice can be used to investigate the potential pathophysiological impact of the Plg-A620T mutation.

Topics: Amino Acid Substitution; Animals; Brain Ischemia; Conjunctivitis; Disease Models, Animal; Female; Fibrin; Fibrinolysin; Gene Expression; Gene Knock-In Techniques; Humans; Male; Mice; Mice, Transgenic; Mutation; Phenotype; Plasminogen; Protein S; Pulmonary Embolism; Skin Diseases, Genetic; Stroke; Venous Thromboembolism; Venous Thrombosis; Wound Healing

Venous thromboembolism is a major contributor to global disease burden. Leukocytes and platelets initiate thrombogenesis on blood stasis and initiate the formation of a fibrin, VWF (von Willebrand factor), and neutrophil extracellular trap scaffold for erythrocytes. However, there is little knowledge on how erythrocytes become stably incorporated into this scaffold. Recently, we described the adhesion of calcium-loaded erythrocytes to endothelial-derived VWF strings. Because VWF is part of the scaffold of venous thrombi, we questioned whether reduced flow or stasis promotes the adhesion of normal erythrocytes to VWF and whether venous thrombi show evidence of erythrocyte-VWF interactions.. In the present work, we perfused, under controlled shear conditions, washed, normal erythrocytes over surface-immobilized plasma and extracellular matrix proteins and showed that normal erythrocytes specifically bind to VWF. The interaction between erythrocytes and VWF significantly increased when the wall shear stress was reduced. Next, we investigated whether erythrocyte-VWF interactions support the structure of venous thrombi. High-resolution immunofluorescence imaging of human venous thrombi showed a striking pattern between erythrocytes, VWF, and fibrin, which suggests that VWF plays a supporting role, linking erythrocytes to fibrin in the thrombus.. Our data suggest that erythrocyte retention in venous thrombi is mediated by erythrocyte-VWF or erythrocyte-VWF-fibrin interactions. Targeting erythrocyte retention could be a new strategy in the treatment or prevention of venous thrombosis.

Topics: Blood Flow Velocity; Calcium; Cell Adhesion; Erythrocytes; Fibrin; Fluorescent Antibody Technique; Humans; Mechanotransduction, Cellular; Regional Blood Flow; Stress, Mechanical; Time Factors; Venous Thrombosis; von Willebrand Factor

The large orthopedic operations are associated with high risk of development of thrombosis of deep veins of lower extremities. Nowadays, new oral anticoagulants are widely applied for anti-thrombotic prevention. The coagulation alterations against the background of effect of Dabigatran, a direct inhibitor of thrombin were examined in 30 patients underwent endoprosthesis replacement of knee joint. The routine clotting indices, fibrinopeptid A, soluble fibrin-monomeric complexes, D-dimer. The samples of blood were selected before operation, after 30 minutes, and at 1st, 3d, 7th and 14th day after endoprosthesis replacement of knee joint. It is demonstrated that routine clotting tests and also detection of D-dimer and soluble fibrin-monomeric complexes provide no adequate evaluation of coagulation activity in patients underwent large orthopedic operation. The concentration of specific marker of fibrin formation of fibrinopeptid A continues to be increased no less than two weeks after endoprosthesis replacement of knee joint that testifies keeping hyper-coagulation and risk of thrombosis. The intake of Dabigatran etexilate in fixed dosage does not exclude development of thrombosis of deep veins of lower extremities that substantiates point of view concerning usefulness of individualization of anti-thrombotic prevention in case of application of new oral anti-coagulants.

Topics: Anticoagulants; Arthroplasty, Replacement, Knee; Blood Coagulation; Blood Coagulation Tests; Dabigatran; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinopeptide A; Humans; Knee Joint; Male; Middle Aged; Postoperative Complications; Thrombin; Venous Thrombosis

A novel heterozygous variant, FGA c.169_180+2 del (designated fibrinogen Shanghai), was identified in a patient with dysfibrinogenemia with antiphospholipid antibody syndrome (APS) and recurrent venous thrombosis, and in his asymptomatic father. We aimed to reveal the functional implication of structural change caused by this variant.. Transcription analysis was performed with FGA minigene transfection assay to evaluate the impact of nucleosides deletion on mRNA editing. The fibrinogen isolated from propositus' plasma was used to characterise its functional defects. Fibrin polymerization and clot lysis experiments were performed by optical measurement of turbidity. Thrombin-catalysed fibrinopeptide release was analysed by the reversed-phase, high-performance liquid chromatography. The ultrastructures of fibrin clots were visualised by scanning electron microscopy.. FGA c.169_180+2 del led to an aberrant mRNA with exon 2 skipping and encoded an shortened Aα chain with 42 amino acids truncation at its N-terminal. The propositus' fibrinogen had an impaired release of fibrinopeptide A and abnormal polymerization with a significantly prolonged lag time, a slower maximum slope and reduced final turbidity. The fibrin clot formed with propositus' fibrinogen showed thicker fibres with looser network structure. Clot lysis was normal using the purified fibrinogen but was significantly impaired using the plasma sample from propositus, compared with that from his father.. Fibrinogen Shanghai results in N-terminal truncation of Aα chain, which does not interfere with synthesis, assembly or secretion of fibrinogen, but compromises fibrin polymerization and clot formation. APS at least partially contributes to the development of thrombosis in the propositus.

Topics: Afibrinogenemia; Antiphospholipid Syndrome; China; Fibrin; Fibrinogen; Humans; Male; Mutation; Venous Thrombosis; Young Adult

Although portal vein thrombosis in cirrhotic patients is frequently observed, the\ detailed process remains to be clarified, and the role of anticardiolipin antibody in the development of\ portal vein thrombosis has been controversial.. A 52-year-old man, who had been diagnosed with alcoholic cirrhosis of the liver, was\ admitted to our hospital suffering from dyspnea and ascites. Just after being diagnosed as having\ antiphospholipid antibody syndrome with lung thrombosis and delivering a positive result for the β\ 2-glycoprotein I-dependent anticardiolipin antibody, he sustained rupture of the esophageal varices\ with rapid development of portal vein thrombosis, which resolved under anticoagulant therapy. Two\ years later, he was admitted again on suspicion of thrombosis because of an elevation in the serum\ D-dimer level, and computed tomography showed portal and upper mesenteric vein thrombosis.\ Although immediate anticoagulant therapy resulted in complete recanalization, he suffered the same\ episode 2 months later, which occurred with re-elevation of the serum D-dimer level.. A positive finding of an anticardiolipin antibody in cirrhotic patients has been considered\ to be nonspecific and not related to the development of thrombus in the portal vein. This case,\ however, seems to indicate that cirrhotic patients with the β2-glycoprotein I-dependent\ anticardiolipin antibody should be regarded as being at high risk for portal vein thrombosis. Monitoring\ with the serum D-dimer was useful in detecting portal vein thrombosis in its early stage.

Topics: Antiphospholipid Syndrome; Fibrin; Fibrinogen; Humans; Liver Cirrhosis; Male; Middle Aged; Portal Vein; Tomography, X-Ray Computed; Venous Thrombosis

Fibrin degradation results in the formation of fibrin degradation products (FDPs) of different molecular weights, which include D-dimer. Commercial D-dimer assays recognize multiple forms of FDP with different specificity. As a result, the absence of an international D-dimer standard and the marked discrepancy in the D-dimer values in the same samples measured by assays from different manufacturers have become the primary problems that clinicians face in the D-dimer determination. We consider that an assay with equal specificity to all FDP forms regardless of their molecular weights could help to solve these problems. We aimed to produce mAbs that could equally recognize high-molecular-weight FDP (HMW FDP) and D-dimer. mAbs against D-dimer were produced. The HMW FDP/D-dimer ratios in plasma samples were analyzed following protein separation by gel filtration using the developed fluoroimmunoassay. A sandwich immunoassay with equal specificity to HMW FDP and D-dimer was developed and applied to determine HMW FDP/D-dimer ratios in patients with different diseases. Although the HMW FDP levels prevailed in thrombotic patients, the FDP and D-dimer levels were comparable in septic patients. Meanwhile, the D-dimer levels often exceeded the HMW FDP levels in patients who had undergone surgery. The 'D-dimer' levels that were detected by different assays also varied greatly depending on the assay specificities to FDP and D-dimer. Our findings show that the introduction of assays with equal specificities to FDP and D-dimer in clinical practice is a possible way of standardizing D-dimer measurements.

Topics: Abdominal Cavity; Animals; Antibodies, Monoclonal; Antibody Specificity; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinolysis; Humans; Hybridomas; Immunoassay; Mice; Mice, Inbred BALB C; Molecular Weight; Reagent Kits, Diagnostic; Sepsis; Spleen; Venous Thrombosis

Factor XIII (FXIII) cross-links fibrin upon activation by thrombin. Activation involves cleavage at residue 37 by thrombin, releasing an activation peptide. A common polymorphism (valine to leucine variant at residue 34, V34L), located in the activation peptide, has been associated with increased activation rates and paradoxically a protective effect in cardiovascular disease. There is, currently, no data available on the effects of V34L from in vivo models of thrombosis. We examined the effect of FXIII V34L on clot formation and cross-linking in vivo.. We generated a panel of full-length recombinant human FXIII-A2 variants with amino acid substitutions in the activation peptide to investigate the effect of these variants on activation rate, and we used wild-type, V34L, and alanine to glycine variant at residue 33 variants to study the effects of varying FXIII activation rate on thrombus formation in a murine model of FeCl3 injury. FXIII activation assay showed that residues 29, 30, 33, and 34 play a critical role in thrombin interaction. Full-length recombinant human FXIII-A2 V34L has significant effects on clot formation, structure, and lysis in vitro, using turbidity assay. This variant influenced fibrin cross-linking but not size of the thrombus in vivo.. Mutations in the activation peptide of full-length recombinant FXIII regulate activation rates by thrombin, and V34L influences in vivo thrombus formation by increased cross-linking of the clot.

Topics: Amino Acid Substitution; Animals; Blood Coagulation; Blood Coagulation Tests; Disease Models, Animal; Factor XIII Deficiency; Factor XIIIa; Fibrin; Genotype; Humans; Male; Mice, 129 Strain; Mice, Inbred CBA; Mice, Knockout; Mutation; Phenotype; Recombinant Proteins; Thrombin; Time Factors; Venous Thrombosis

The postthrombotic syndrome (PTS) is a severe complication of deep vein thrombosis (DVT). Reduced plasma clot permeability and lysability have been linked to DVT and residual vein obstruction. OBJECTIVES We investigated whether altered fibrin clot properties are associated with the occurrence of PTS.. Plasma fibrin clot permeability (Ks ) and lysability were investigated in a cohort of 197 consecutive patients aged 18 to 65 years recruited 3 months following the first-ever DVT. Patients with severe thrombophilia or comorbidities known to adversely affect clot phenotype were ineligible.. During a 1-year follow-up PTS developed in 48 (24%) patients, who were characterized by lower Ks , prolonged fibrin clot lysis time (CLT) and slower release of D-dimer from clots (D-Drate ), together with higher plasma D-dimer, C-reactive protein and thrombin-activatable fibrinolysis inhibitor (TAFI). No PTS-associated differences in fibrinogen, thrombin generation, factor VIII, other fibrinolysis proteins and the quality of anticoagulation were observed. Ks (r = -0.71), CLT (r = 0.45), D-Drate (r = -0.30) and TAFI activity (r = 0.38) were associated with the Villalta scale (all P < 0.05). Recurrent VTE occurred also more commonly in PTS patients during follow-up and the 26 (13.2%) patients had lower Ks , longer CLT and lower D-Drate (all P < 0.05). A multivariate model adjusted for age, body mass index, fibrinogen and glucose showed that independent predictors of PTS were idiopathic DVT, plasma D-dimer, Ks , D-Drate , tissue plasminogen activator and TAFI activity.. This study demonstrates that formation of more compact fibrin clots displaying impaired susceptibility to lysis predisposes to PTS.

Topics: Adolescent; Adult; Aged; Blood Coagulation; Cohort Studies; Female; Fibrin; Fibrin Clot Lysis Time; Fibrinolysis; Follow-Up Studies; Humans; Male; Middle Aged; Permeability; Postthrombotic Syndrome; Risk; Thrombin; Veins; Venous Thrombosis; Young Adult

According to recent reports, a common polymorphism resulting in Val to Leu substitution, located 3 amino acids (Val34Leu) upstream of the thrombin cleavage site of FXIII A, has been related to a lower incidence of deep vein thrombosis (DVT). And, a different expression pattern has been shown across nations and races. However, the frequency of FXIII polymorphism expression in Koreans has not been reported in normal individuals or DVT-patient groups.. Case-control study in Korean population.. We investigated the distribution of factor XIII Val34Leu polymorphisms in Korean patients of DVT (50 cases) and Korean healthy controls (100 cases), using real-time polymerase chain reaction for single nucleotide polymorphism genotyping.. With regard to the frequency of the FXIII polymorphism in DVT patients and in the general control group, all 50 cases in the patient group and 100 cases in the control group were found to be Val34 homozygotes.. The Val34Leu polymorphism of FXIII was not found in Korean people, and compared with Caucasians, a noticeably low incidence of DVT was shown. Thus, the preventive effect of the Val34 allele of FXIII on the formation of thrombi was shown.

Topics: Asian People; Case-Control Studies; Factor XIII; Female; Fibrin; Gene Frequency; Genetic Association Studies; Genetic Predisposition to Disease; Homozygote; Humans; Incidence; Male; Middle Aged; Phenotype; Polymorphism, Single Nucleotide; Protective Factors; Republic of Korea; Risk Factors; Venous Thrombosis; White People

Deep vein thrombosis (DVT) and its sequela, pulmonary embolism, occur at a rate of 1 per 1000 person/year. Experimental models for evaluation of DVT have many short-comings, such as mechanical occlusion or stenosis to cause thrombosis, rather than the clinical scenario of thrombosis causing occlusion/stenosis. The goal of this study was to develop a model of flow-based large-vein thrombosis with resistance to resolution, to model clinical DVT behavior. Adult male C57Bl/6 mice underwent thrombus induction via an electrolytic injury to the femoral vein (3V positive current for 90s), with subsequent intra-vital fluorescence quantitation of platelet and fibrin accumulation through the first 60 min, and final histomorphometric volume evaluation at 1, 7, 14, and 28 days. Platelet accumulation at the injury site was comparable to a milder electrolytic injury, whereas fibrin was greatly augmented by 60 min in the more severe injury model. Thrombi showed persistent presence at 1 and 7 days, with remodeling to a stenotic fibrosis that encroached into the lumen at 14 and 28 days. The thrombotic/fibrotic volume within the femoral vein fell by 23% from 1 to 7 days, but had a residual presence at 28 days that was 31% the 1-day volume. This new model may provide an alternative approach to evaluating DVT persistence and therapeutic inhibition, to develop a better understanding of the clinical progression of DVT to thrombophlebitis.

Topics: Animals; Blood Platelets; Disease Models, Animal; Femoral Vein; Fibrin; Male; Mice; Mice, Inbred C57BL; Venous Thrombosis

Recently, platelets, neutrophils, and factor XII (FXII) have been implicated as important players in the pathophysiology of venous thrombosis. Their role became evident in mouse models in which surgical handling was used to provoke thrombosis. Inhibiting anticoagulation in mice by using small interfering RNA (siRNA) targeting Serpinc1 and Proc also results in a thrombotic phenotype, which is spontaneous (no additional triggers) and reproducibly results in clots in the large veins of the head and fibrin deposition in the liver. This thrombotic phenotype is fatal but can be fully rescued by thrombin inhibition. The mouse model was used in this study to investigate the role of platelets, neutrophils, and FXII. After administration of siRNAs targeting Serpinc1 and Proc, antibody-mediated depletion of platelets fully abrogated the clinical features as well as microscopic aspects in the head. This was corroborated by strongly reduced fibrin deposition in the liver. Whereas neutrophils were abundant in siRNA-triggered thrombotic lesions, antibody-mediated depletion of circulating Ly6G-positive neutrophils did not affect onset, severity, or thrombus morphology. In addition, absence of circulating neutrophils did not affect quantitative liver fibrin deposition. Remarkably, siRNA-mediated depletion of plasma FXII accelerated the onset of the clinical phenotype; mice were affected with more severe thrombotic lesions. To summarize, in this study, onset and severity of the thrombotic phenotype are dependent on the presence of platelets but not circulating neutrophils. Unexpectedly, FXII has a protective effect. This study challenges the proposed roles of neutrophils and FXII in venous thrombosis pathophysiology.

Topics: Animals; Antigens, Ly; Antithrombin III; Blood Platelets; Factor XII; Female; Fibrin; Liver; Mice; Neutrophils; RNA, Small Interfering; Venous Thrombosis

Pregnancy-related deep vein thrombosis (DVT) is most common during the late phase of pregnancy and the first 6-weeks postpartum. Pregnancy-related DVT can have long-term complications, specifically post-thrombotic syndrome (PTS). Fibrin network ultrastructure is altered during pregnancy and post-partum. It is therefore essential to evaluate fibrin fiber diameter during and after pregnancy as this may provide insight into pregnancy-related DVT and subsequent PTS.. The fibrin network ultrastructure of females during different phases of pregnancy was compared to that of non-pregnant females to assess possible changes to the fibrin network morphology and fibrin fiber diameter using scanning electron microscopy micrographs.. The fibrin network arrangement was more densely packed during different phases of pregnancy, corresponding to earlier findings. Fibrin diameter decreased significantly during pregnancy, with the greatest decrease occurring during the late phase of pregnancy. The fractal dimensions of fibrin micrographs increased significantly during pregnancy compared to nonpregnant females. These changes are indicative of a simultaneous hypercoagulable and hypofibrinolytic state and correspond to the increased risk of DVT and subsequent development of PTS.. It is critical to identify "vulnerable" females with an inflammatory predisposition to prevent possible DVT and subsequent PTS. Modifiable risk factors like obesity and smoking should be addressed to alleviate the burden on the coagulation system. Morphological and viscoelastic techniques are crucial in assessing the coagulatory health of females during pregnancy.

Topics: Adolescent; Adult; Female; Fibrin; Humans; Microscopy, Electron, Scanning; Postthrombotic Syndrome; Pregnancy; Pregnancy Complications, Hematologic; Venous Thrombosis; Young Adult

Antithrombin (AT) deficiency is an autosomal dominant disorder, and identification of mutation AT variants would improve our understanding of the anticoagulant function of this serine protease inhibitor (SERPIN) and the molecular pathways underlying this disorder. In the present study, we performed whole-exome sequencing of a Chinese family with deep vein thrombosis, and identified a new small deletion that eliminates four amino acids (INEL) from exon 4 of SERPINC1 gene. This causes type I AT deficiency by enhancing the intracellular retention of this protein. AT retention leads to endoplasmic reticulum (ER) stress, which further inhibits AT release. In addition, ER stress activates ER-associated degradation, which promotes AT degradation. Suppression of ER stress enhanced the secretion of AT, while inhibition of ER-associated degradation suppressed AT release. Thus, our study identified a new mutation (INEL deletion) causing type I AT deficiency, and uncovered a novel mechanism for AT retention through enhanced ER stress, which may provide an innovative approach for treating AT deficiency.

Topics: Antithrombin III; China; Endoplasmic Reticulum Stress; Exome Sequencing; Female; Fibrin; Humans; Male; Pedigree; Sequence Deletion; Venous Thrombosis

Aptamers are oligonucleotides targeting protein-protein interactions with pharmacokinetic profiles and activity reversal options. Although P-selectin and von Willebrand factor (vWF) have been implicated in the development of venous thrombosis (VT), no studies have directly compared aptamer efficacy with standard of care in VT. In this study, ARC5692, an anti-P-selectin aptamer, and ARC15105, an anti-vWF aptamer, were compared with low-molecular-weight heparin, enoxaparin, to test the efficacy of P-selectin or vWF inhibition in promoting thrombus resolution and preventing vein wall fibrosis, in a baboon model of VT.. Groups were as follows: treatment arm: animals received P-selectin or vWF aptamer inhibitors or enoxaparin (n=3 per group). Controls received no treatment (n=3). Prophylactic arm: animals received P-selectin inhibitor (n=4) or vWF inhibitor (n=3). Treatment arm: P-selectin-inhibitor demonstrated a significant improvement in vein recanalization by magnetic resonance venography (73% at day 21), and significantly decreased vein wall collagen, compared with all groups. Anti-P-selectin equaled enoxaparin in maintaining valve competency by ultrasound. All control animals had compromised valve competency post thrombosis. Prophylactic arm: animals receiving P-selectin and vWF inhibitors demonstrated improved vein recanalization by magnetic resonance venography versus controls (80% and 85%, respectively, at day 21). Anti-P-selectin protected iliac valve function better than anti-vWF, and both improved valve function versus controls. No adverse bleeding events were observed.. The P-selectin inhibitor aptamer promoted iliac vein recanalization, preserved valve competency, and decreased vein wall fibrosis. The results of this work suggest that P-selectin inhibition maybe an ideal target in the treatment and prophylaxis of deep VT, warranting clinical trials.

Topics: Animals; Aptamers, Nucleotide; Blood Coagulation; Collagen; Disease Models, Animal; Enoxaparin; Fibrin; Fibrinolytic Agents; Fibrosis; Iliac Vein; Leukocytes; Magnetic Resonance Angiography; P-Selectin; Papio; Phlebography; Platelet Aggregation; Time Factors; Ultrasonography; Venous Thrombosis; Venous Valves; von Willebrand Factor

The diagnosis of deep venous thromboembolic disease is still challenging despite the progress of current thrombus imaging modalities and new diagnostic algorithms. We recently reported the high target uptake and thrombus imaging efficacy of the novel fibrin-specific PET probe (64)Cu-FBP8. Here, we tested the feasibility of (64)Cu-FBP8 PET to detect source thrombi and culprit emboli after deep vein thrombosis and pulmonary embolism (DVT-PE). To support clinical translation of (64)Cu-FBP8, we performed a human dosimetry estimation using time-dependent biodistribution in rats.. Sprague-Dawley rats (n = 7) underwent ferric chloride application on the femoral vein to trigger thrombosis. Pulmonary embolism was induced 30 min or 2 d after DVT by intrajugular injection of a preformed blood clot labeled with (125)I-fibrinogen. PET imaging was performed to detect the clots, and SPECT was used to confirm in vivo the location of the pulmonary emboli. Ex vivo γ counting and histopathology were used to validate the imaging findings. Detailed biodistribution was performed in healthy rats (n = 30) at different time points after (64)Cu-FBP8 administration to estimate human radiation dosimetry. Longitudinal whole-body PET/MR imaging (n = 2) was performed after (64)Cu-FBP8 administration to further assess radioactivity clearance.. (64)Cu-FBP8 PET imaging detected the location of lung emboli and venous thrombi after DVT-PE, revealing significant differences in uptake between target and background tissues (P < 0.001). In vivo SPECT imaging and ex vivo γ counting confirmed the location of the lung emboli. PET quantification of the venous thrombi revealed that probe uptake was greater in younger clots than in older ones, a result confirmed by ex vivo analyses (P < 0.001). Histopathology revealed an age-dependent reduction of thrombus fibrin content (P = 0.006), further supporting the imaging findings. Biodistribution and whole-body PET/MR imaging showed a rapid, primarily renal, body clearance of (64)Cu-FBP8. The effective dose was 0.021 mSv/MBq for males and 0.027 mSv/MBq for females, supporting the feasibility of using (64)Cu-FBP8 in human trials.. We showed that (64)Cu-FBP8 PET is a feasible approach to image DVT-PE and that radiogenic adverse health effects should not limit the clinical translation of (64)Cu-FBP8.

Topics: Algorithms; Animals; Copper Radioisotopes; Female; Fibrin; Male; Positron-Emission Tomography; Pulmonary Embolism; Radiometry; Rats; Rats, Sprague-Dawley; Thrombosis; Tissue Distribution; Tomography, Emission-Computed, Single-Photon; Venous Thrombosis; Whole Body Imaging

Thrombosis is a leading cause of morbidity and mortality worldwide. Current diagnostic strategies rely on imaging modalities that are specific for distinct vascular territories, but a thrombus-specific whole-body imaging approach is still missing. Moreover, imaging techniques to assess thrombus composition are underdeveloped, although therapeutic strategies may benefit from such technology. Therefore, our goal was to test whether positron emission tomography (PET) with the fibrin-binding probe (64)Cu-FBP8 allows multisite thrombus detection and fibrin content estimation.. Thrombosis was induced in Sprague-Dawley rats (n=32) by ferric chloride application on both carotid artery and femoral vein. (64)Cu-FBP8-PET/CT imaging was performed 1, 3, or 7 days after thrombosis to detect thrombus location and to evaluate age-dependent changes in target uptake. Ex vivo biodistribution, autoradiography, and histopathology were performed to validate imaging results. Arterial and venous thrombi were localized on fused PET/CT images with high accuracy (97.6%; 95% confidence interval, 92-100). A single whole-body PET/MR imaging session was sufficient to reveal the location of both arterial and venous thrombi after (64)Cu-FBP8 administration. PET imaging showed that probe uptake was greater in younger clots than in older ones for both arterial and venous thrombosis (P<0.0001). Quantitative histopathology revealed an age-dependent reduction of thrombus fibrin content (P<0.001), consistent with PET results. Biodistribution and autoradiography further confirmed the imaging findings.. We demonstrated that (64)Cu-FBP8-PET is a feasible approach for whole-body thrombus detection and that molecular imaging of fibrin can provide, noninvasively, insight into clot composition.

Topics: Animals; Arterial Occlusive Diseases; Biopsy, Needle; Copper Radioisotopes; Disease Models, Animal; Fibrin; Image Processing, Computer-Assisted; Immunohistochemistry; Male; Positron-Emission Tomography; Random Allocation; Rats; Rats, Sprague-Dawley; Sensitivity and Specificity; Venous Thrombosis; Whole Body Imaging

Widely incorporated into vascular surgery pharmacological thrombolysis in treatment for deep vain thrombosis is fraught with a series of unsolved problems requiring further consideration. In spite of aggressive nature of treatment in a series of cases pharmacological thrombolysis sometimes turns out ineffective. Along with it, the results of experimental studies suggest a possibility of accelerating resorption of thrombotic masses and inhibiting remodelling of the venous wall by means of influencing effector cells of endogenous thrombolysis. A detailed study of the mechanisms of thrombolysis would make it possible to formulate strict criteria for carrying out pharmacological thrombolysis and to increase its efficacy.. Широко вошедший в сосудистую хирургию фармакологический тромболизис при лечении тромбоза глубоких вен таит ряд нерешенных вопросов, нуждающихся в дальнейшем рассмотрении. Вопреки агрессивности лечения в ряде случаев фармакологический тромболизис оказывается малоэффективным. Вместе с тем результаты экспериментальных исследований свидетельствуют о возможности ускорения резорбции тромботических масс и угнетения ремоделирования венозной стенки посредством влияния на клетки-эффекторы эндогенного тромболизиса. Детальное изучение механизмов ферментативного лизиса тромба позволит сформулировать строгие критерии проведения фармакологического тромболизиса и повысить его эффективность.

Topics: Antithrombins; Catheterization, Peripheral; Combined Modality Therapy; Fibrin; Fibrinolysis; Humans; Outcome Assessment, Health Care; Thrombolytic Therapy; Venous Thrombosis

Deep vein thrombosis and the risk of pulmonary embolism are significant causes of morbidity and mortality. Much remains unclear, however, about the mechanisms by which a venous thrombus initiates, progresses, or resolves. In particular, there is a pressing need to characterize the evolving mechanical properties of a venous thrombus for its mechanical integrity is fundamental to many disease sequelae.. The primary goal of the present study was to initiate a correlation between evolving histological changes and biomechanical properties of venous thrombus.. We employed an inferior vena cava ligation model in mice to obtain cylindrical samples of thrombus that were well suited for mechanical testing and that could be explanted at multiple times following surgery. Using uniaxial micro-mechanical testing, we collected stress-stretch data that were then fit with a microstructurally-inspired material model before submitting the samples to immunohistological examination.. We found that venous thrombus underwent a radially inward directed replacement of fibrin with collagen between 2 weeks and 4 weeks of development, which was accompanied by the infiltration of inflammatory and mesenchymal cells. These histological changes correlated with a marked increase in material stiffness.. We demonstrated that 2 to 4 week old venous thrombus undergoes drastic remodeling from a fibrin-dominated mesh to a collagen-dominated microstructure and that these changes are accompanied by dramatic changes in biomechanical behavior.

Topics: Animals; Biomechanical Phenomena; Collagen; Disease Models, Animal; Fibrin; Humans; Male; Mice; Mice, Inbred C57BL; Vascular Remodeling; Vena Cava, Inferior; Venous Thrombosis

Fibrinolytic therapy of venous thromboembolism (VTE) is increasingly utilized, yet limited knowledge is available regarding in vivo mechanisms that govern fibrinolytic efficacy. In particular, it is unknown how age-dependent thrombus organization limits direct blood contact with fibrin, the target of blood-based fibrinolytic agents. Utilizing high-resolution in vivo optical molecular imaging with FTP11, a near-infrared fluorescence (NIRF) fibrin-specific reporter, here we investigated the in vivo interrelationships of blood accessibility to fibrin, thrombus age, thrombus neoendothelialization, and fibrinolysis in murine venous thrombosis (VT). In both stasis VT and non-stasis VT, NIRF microscopy showed that FTP11 fibrin binding was thrombus age-dependent. FTP11 localized to the luminal surface of early-stage VT, but only minimally to subacute VT (p<0.001). Transmission electron microscopy of early stage VT revealed direct blood cell contact with luminal fibrin-rich surfaces. In contrast, subacute VT exhibited an encasing CD31+ neoendothelial layer that limited blood cell contact with thrombus fibrin in both VT models. Next we developed a theranostic strategy to predict fibrinolytic efficacy based on the in vivo fibrin accessibility to blood NIRF signal. Mice with variably aged VT underwent FTP11 injection and intravital microscopy (IVM), followed by tissue plasminogen activator infusion to induce VT fibrinolysis. Fibrin molecular IVM revealed that early stage VT, but not subacute VT, bound FTP11 (p<0.05), and experienced higher rates of fibrinolysis and total fibrinolysis (p<0.05 vs. subacute VT). Before fibrinolysis, the baseline FTP11 NIRF signal predicted the net fibrinolysis at 60 minutes (p<0.001). Taken together, these data provide novel insights into the temporal evolution of VT and its susceptibility to therapeutic fibrinolysis. Fibrin molecular imaging may provide a theranostic strategy to identify venous thrombi amenable to fibrinolytic therapies.

Topics: Animals; Disease Models, Animal; Fibrin; Fibrinolytic Agents; Indoles; Male; Mice, Inbred C57BL; Molecular Imaging; Oligopeptides; Staining and Labeling; Thrombosis; Venous Thrombosis

The factors that contribute to pulmonary embolism (PE), a potentially fatal complication of deep vein thrombosis (DVT), remain poorly understood. Whereas fibrin clot structure and functional properties have been implicated in the pathology of venous thromboembolism and the risk for cardiovascular complications, their significance in PE remains uncertain. Therefore, we systematically compared and quantified clot formation and lysis time, plasminogen levels, viscoelastic properties, activated factor XIII cross-linking, and fibrin clot structure in isolated DVT and PE subjects. Clots made from plasma of PE subjects showed faster clot lysis times with no differences in lag time, rate of clot formation, or maximum absorbance of turbidity compared with DVT. Differences in lysis times were not due to alterations in plasminogen levels. Compared with DVT, clots derived from PE subjects showed accelerated establishment of viscoelastic properties, documented by a decrease in lag time and an increase in the rate of viscoelastic property formation. The rate and extent of fibrin cross-linking by activated factor XIII were similar between clots from DVT and PE subjects. Electron microscopy revealed that plasma fibrin clots from PE subjects exhibited lower fiber density compared with those from DVT subjects. These data suggest that clot structure and functional properties differ between DVT and PE subjects and provide insights into mechanisms that may regulate embolization.

Topics: Adult; Aged; Blood Coagulation; Cross-Linking Reagents; Elasticity; Factor XIIIa; Female; Fibrin; Fibrinogen; Fibrinolysis; Humans; Male; Microscopy, Electron, Scanning; Middle Aged; Plasminogen; Prospective Studies; Pulmonary Embolism; Venous Thrombosis

Deep venous thrombosis is a major health problem. Thrombolytic therapies are effective in recanalizing the veins and preventing post-thrombotic complications, but there is no consensus on selection criteria. The aim of this study was to investigate a fibrin-specific MRI contrast agent (EP-2104R) for the accurate quantification of thrombus' fibrin content in vivo and for the identification of thrombus suitable for thrombolysis.. Venous thrombosis was induced in the inferior vena cava of 8- to 10-week-old male BALB/C mice and MRI performed 2, 4, 7, 10, 14, and 21 days later. Eighteen mice were scanned at each time point pre and 2 hours post injection of EP-2104R (8.0 μmol/kg) with 12 mice at each time point used to correlate fibrin contrast uptake with thrombus' histological stage and fibrin content. Six mice at each time point were immediately subjected to intravascular thrombolytic therapy (10 mg/kg of tissue-type plasminogen activator). Mice were imaged to assess response to lytic therapy 24 hours after thrombolytic treatment. Two mice at each time point were scanned post injection of 0.2 mmol/kg of Gd-DTPA (gadolinium with diethylenetriaminepentacetate, Magnevist, Schering AG, Berlin, Germany) for control purpose. Contrast uptake was correlated positively with the fibrin content of the thrombus measured by Western blotting (R(2)=0.889; P<0.001). Thrombus relaxation rate (R1) post contrast and the change in visualized thrombus size on late gadolinium enhancement inversion recovery MRI pre-EP-2104R and post-EP-2104R injection were the best predictors for successful thrombolysis (area under the curve, 0.989 [95% confidence interval, 0.97-1.00] and 0.994 [95% confidence interval, 0.98-1.00] respectively).. MRI with a fibrin-specific contrast agent accurately estimates thrombus fibrin content in vivo and identifies thrombi that are amenable for thrombolysis.

Topics: Animals; Fibrin; Gadolinium; Magnetic Resonance Imaging; Male; Mice; Mice, Inbred BALB C; Peptides; Thrombolytic Therapy; Venous Thrombosis

C-reactive protein (CRP) promotes tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) expression in vitro, and an elevated plasma CRP concentration is associated with an increased risk of vein graft (VG) thrombosis after coronary artery bypass surgery. However, little is known about the effects of CRP on VG TF and PAI-1 expression in vivo, or on VG thrombosis.. We studied transgenic (Tg) mice expressing human CRP in a VG model to explore in vivo cause-and-effect relationships between CRP and TF, PAI-1, and VG thrombosis.. Vein segments from wild-type (WT) and CRP-Tg donors were transplanted into carotid arteries of WT and CRP-Tg recipients. VGs were analyzed 1-4 weeks later.. Human CRP accumulated in VGs during the first 4 weeks after surgery, but appeared to originate exclusively from systemic sources, rather than local production. Human CRP significantly increased TF gene expression, protein concentration and activity in VGs. Human CRP also increased PAI-1 concentrations in VGs, although only in vascular endothelial cells. Human CRP stimulated macrophage migration, invasion into VGs, and TF expression. Fibrin deposition was significantly greater in VGs of CRP-Tg mice than in WT controls.. CRP accumulates in VGs early after surgery, originating from systemic sources rather than local synthesis. Human CRP promotes TF and PAI-1 expression in VGs, although with different expression patterns. Human CRP stimulates macrophage invasion and fibrin deposition within VGs. These results suggest that CRP induces pathologic changes in VGs that contribute to early VG occlusion.

Topics: Animals; C-Reactive Protein; Cell Movement; Chlorides; Coronary Artery Bypass; Ferric Compounds; Fibrin; Humans; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Plasminogen Activator Inhibitor 1; Recombinant Proteins; Thromboplastin; Transgenes; Veins; Venous Thrombosis

Pharmacologic inhibition of platelet activation and aggregation is a mainstay for reducing the incidence of arterial thrombosis, whereas anticoagulation is the primary approach for preventing the development of venous thrombosis. The effect of standard pharmacologic agents on their reciprocal vessel - anticoagulants on arterial thrombosis and platelet inhibitor on venous thrombosis - is relatively understudied. This study was designed to evaluate murine large-vessel arterial or venous thrombosis under conditions of either fibrin or platelet inhibition. In this study, heparin and clopidogrel were used as standard anticoagulant and platelet inhibitor, respectively, evaluating both large artery and vein thrombosis in mice, using in-vivo fluorescence imaging to simultaneously measure fibrin and platelet levels at the thrombus induction site. Heparin reduced both fibrin and platelet development in both arteries and veins, with stronger influences on fibrin accrual. Clopidogrel had a stronger effect in arteries, reducing both platelet and fibrin accumulation. Clopidogrel also reduced platelet accumulation with venous thrombosis, but the reductions in fibrin formation did not reach statistical significance. These findings illustrate the interactive role of platelet activity and coagulation in the development of large-vessel thrombosis, with inhibition of one thrombotic component showing profound effects on the other component in both arterial and venous thrombosis.

Topics: Animals; Anticoagulants; Blood Coagulation; Blood Platelets; Clopidogrel; Disease Models, Animal; Drug Interactions; Fibrin; Heparin; Male; Mice; Mice, Inbred C57BL; Platelet Activation; Platelet Aggregation Inhibitors; Ticlopidine; Venous Thrombosis

Deep vein thrombosis remains a major health problem necessitating accurate diagnosis. Thrombolysis is associated with significant morbidity and is effective only for the treatment of unorganized thrombus. We tested the feasibility of in vivo magnetization transfer (MT) and diffusion-weighted magnetic resonance imaging to detect thrombus organization in a murine model of deep vein thrombosis.. Deep vein thrombosis was induced in the inferior vena cava of male BALB/C mice. Magnetic resonance imaging was performed at days 1, 7, 14, 21, and 28 after thrombus induction using MT, diffusion-weighted, inversion-recovery, and T1-mapping protocols. Delayed enhancement and T1 mapping were repeated 2 hours after injection of a fibrin contrast agent. Finally, excised thrombi were used for histology. We found that MT and diffusion-weighted imaging can detect histological changes associated with thrombus aging. MT rate (MTR) maps and percentage of MT rate (%MTR) allowed visualization and quantification of the thrombus protein content, respectively. The %MTR increased with thrombus organization and was significantly higher at days 14, 21, and 28 after thrombus induction (days 1, 7, 14, 21, 28: %MTR=2483±451, 2079±1210, 7029±2490, 10 295±4356, 32 994±25 449; PANOVA<0.05). There was a significant positive correlation between the %MTR and the histological protein content of the thrombus (r=0.70; P<0.05). The apparent diffusion coefficient was lower in erythrocyte-rich and collagen-rich thrombus (0.72±0.10 and 0.69±0.05 [×10(-3) mm(2)/s]). Thrombus at days 7 and 14 had the highest apparent diffusion coefficient values (0.95±0.09 and 1.10±0.18 [×10(-3) mm(2)/s]).. MT and diffusion-weighted magnetic resonance imaging sequences are promising for the staging of thrombus composition and could be useful in guiding medical intervention.

Topics: Animals; Collagen; Contrast Media; Diffusion Magnetic Resonance Imaging; Disease Models, Animal; Erythrocytes; Feasibility Studies; Fibrin; Gadolinium; Male; Mice; Mice, Inbred BALB C; Peptides; Predictive Value of Tests; Sensitivity and Specificity; Time Factors; Vena Cava, Inferior; Venous Thrombosis

Individuals with elevated prothrombin, including those with the prothrombin G20210A mutation, have increased risk of venous thrombosis. Although these individuals do not have increased circulating prothrombotic biomarkers, their plasma demonstrates increased tissue factor-dependent thrombin generation in vitro. The objectives of this study were to determine the pathological role of elevated prothrombin in venous and arterial thrombosis in vivo, and distinguish thrombogenic mechanisms in these vessels.. Prothrombin was infused into mice to raise circulating levels. Venous thrombosis was induced by electrolytic stimulus to the femoral vein or inferior vena cava ligation. Arterial thrombosis was induced by electrolytic stimulus or ferric chloride application to the carotid artery. Mice infused with prothrombin demonstrated increased tissue factor-triggered thrombin generation measured ex vivo, but did not have increased circulating prothrombotic biomarkers in the absence of vessel injury. After venous injury, elevated prothrombin increased thrombin generation and the fibrin accumulation rate and total amount of fibrin ≈ 3-fold, producing extended thrombi with increased mass. However, elevated prothrombin did not accelerate platelet accumulation, increase the fibrin accumulation rate, or shorten the vessel occlusion time after arterial injury.. These findings reconcile previously discordant findings on thrombin generation in hyperprothrombinemic individuals measured ex vivo and in vitro, and show elevated prothrombin promotes venous, but not arterial, thrombosis in vivo.

Topics: Animals; Blood Coagulation; Blood Platelets; Carotid Arteries; Chlorides; Disease Models, Animal; Femoral Vein; Ferric Compounds; Fibrin; Humans; Mice; Noxae; Prothrombin; Risk Factors; Thrombophilia; Vena Cava, Inferior; Venous Thrombosis

The relationships among the hemostatic markers, the development of deep vein thrombosis (DVT) and the withdrawal of fondaparinux due to a reduction in the hemoglobin levels were examined.. Two-hundred twenty-one Japanese patients who underwent major orthopedic surgery and were treated with 1.5mg of fondaparinux instead of 2.5mg of fondaparinux were studied. Forty-seven of 221 patients discontinued fondaparinux treatment (withdrawal group) and 37 patients developed DVT.. The age, frequency of total knee arthroplasty (TKA), withdrawal of fondaparinux, reduction of hemoglobin and the plasma levels of soluble fibrin (SF), D-dimer and fibrinogen and fibrin degradation product (FDP) on day 1 after the operation were significantly higher in the patients with DVT. Elevated SF, D-dimer or FDP levels were associated with the risk for DVT. The age, frequency of TKA or DVT, anti-Xa activity and the creatinine, FDP and D-dimer levels were significantly higher in the withdrawal group. An anti-Xa level >0.33 mg/l and an elevated D-dimer or FDP level were associated with the risk of withdrawal.. The age and SF levels, TKA and withdrawal of fondaparinux were related to the risk of DVT, and the anti-Xa activity, creatinine level and DVT were related to the risk of withdrawal of fondaparinux due to a reduction in hemoglobin.

Topics: Age Factors; Aged; Aged, 80 and over; Anemia; Anticoagulants; Arthroplasty, Replacement, Knee; Biomarkers; Factor Xa; Factor Xa Inhibitors; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fondaparinux; Hemoglobins; Humans; Male; Middle Aged; Polysaccharides; Risk Factors; Venous Thrombosis

Collagen is a powerful thrombotic stimulus that functions by direct and indirect binding to various platelet receptors. A variety of collagen types are known and several (e.g., collagen Types I, III, IV) are found in vascular tissues and are exposed upon disruption of the endothelium or more extensive vessel wall rupture. Some murine models of thrombosis purport to expose collagen to initiate thrombosis, however, the nature and extent of this exposure is not clear. This study was undertaken to place a known collagen-dominated surface into the in vivo arterial or venous circulation as a method for direct study of collagen-induced thrombosis in mice. The epigastric artery was removed from donor mice and a microsuture with attached needle was knotted into one cut end. Anesthetized mice had this needle/suture/small-artery inserted into and out of a 0.5-mm length of the larger carotid artery or femoral vein, leaving the collagen-rich adventitial surface of the epigastric artery intralumenally in the larger vessel. Extensive platelet and fibrin deposition on this surface were in evidence and were quantitated with fluorescence imaging; administration of clopidogrel reduced thrombus development in both arteries and veins. A method was developed to evert the epigastric artery and disrupt the exteriorized endothelium; with the same needle/suture vessel-insertion technique, this surface stimulated significantly less thrombotic response in both arteries and veins, suggesting differential thrombogenesis based on the molecular composition of the induction factor. This new model of thrombosis offers a method for directly assessing the role of collagen-mediated thrombosis in murine arteries and veins.

Topics: Animals; Arterial Occlusive Diseases; Blood Coagulation; Blood Platelets; Carotid Arteries; Clopidogrel; Collagen; Disease Models, Animal; Epigastric Arteries; Femoral Vein; Fibrin; Mice; Mice, Inbred C57BL; Platelet Aggregation Inhibitors; Thrombosis; Ticlopidine; Time Factors; Venous Thrombosis

Pulmonary embolectomy is a treatment option in selected patients with high-risk pulmonary embolism (PE). Efficiency of thrombus degradation in PE largely depends on the architecture of its fibrin network, however little is known about its determinants. We present the case of a 56-year-old woman with high-risk PE and proximal deep-vein thrombosis, whose thrombotic material removed during embolectomy from the right atrium and pulmonary (lobar and segmental) arteries has been studied using scanning electron microscopy (SEM). SEM images showed that distally located thrombi are richer in densely-packed fibrin fibers and contain more white cells and less erythrocytes than the proximal ones and the atrial thrombus. Fibrin fibers alignment along the flow vector was observed in the thrombi removed from high-velocity flow pulmonary arteries, and not in the atrial thrombus. The content of denser fibrin network and platelet aggregates was increased in segmental thromboemboli. Our findings describe the relation between thrombus architecture and location, and might help to elucidate thrombus resistance to anticoagulant therapy in some PE patients.

Topics: Anticoagulants; Drug Resistance; Embolectomy; Female; Fibrin; Heart Atria; Humans; Middle Aged; Pulmonary Artery; Venous Thrombosis

The exclusion of deep venous thrombosis (DVT) in the elderly is hampered by low specificity in clinical decision of D-dimer assays in older patients. To reduce false-positive results, we evaluated specific fibrin(ogen) degradation product assays for their contribution in the diagnosis of DVT. In a post-hoc study with outpatients suspected for DVT, we evaluated the elastase-specific fibrinogen (fibrinogen elastase degradation product, FgEDP) and D-E-specific fibrin (fibrin degradation product, FbDP) degradation product assays in relation to DVT. Results were combined with five D-dimer assays as ratio, with a specific focus on age-dependency. In 437 patients (DVT prevalence 39%), FgEDP correlated with D-dimer in DVT-negative patients (P<0.001), but not in DVT-positive patients (P > 0.55). FbDP results correlated with D-dimer in both groups (P<0.001). The values of the area under the curve of the receiver operating characteristic curve for both assays were lower than D-dimer. Using the ratios, only in the fourth age quartile D-dimer/FgEDP ratios had diagnostic value with lower number needed to test (1.8-12.7) as compared to D-dimer less than 500 μg/l alone (5.4-102). The D-dimer/FbDP ratios in DVT-negative elderly patients increased to a plateau by increasing D-dimer. In DVT-positive patients, these ratios were near constant for increasing values of D-dimer. In elderly patients, the D-dimer/FgEDP ratios may improve the number of patients in whom DVT could be excluded. The D-dimer/FbDP ratios showed differences in composition of fibrin degradation products between DVT-negative and DVT-positive patients and between young and old DVT-negative patients.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; False Positive Reactions; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibrinogen; Humans; Male; Middle Aged; Proteolysis; ROC Curve; Venous Thrombosis

Topics: Aged; Anticoagulants; Antifibrinolytic Agents; Blood Coagulation Tests; Female; Fibrin; Fibrinogen; Fibrinolysis; Humans; Male; Middle Aged; Pulmonary Embolism; Risk Factors; Venous Thrombosis

Topics: Adult; Catheterization; Catheters; Device Removal; Echocardiography, Transesophageal; Extracorporeal Membrane Oxygenation; Fibrin; Humans; Male; Venous Thrombosis

Topics: Binding Sites; Blood Coagulation Disorders, Inherited; Family Health; Female; Fibrin; Homozygote; Humans; Infant; Infant, Newborn; Male; Models, Genetic; Mutation; Phenotype; Prevalence; Venous Thrombosis

There are many reports concerning the fondaparinux prophylaxis of deep vein thrombosis (DVT) after surgery, but little is known about the usefulness of diagnosing DVT by the thrombotic markers such as soluble fibrin (SF) and D-dimer in patients treated with fondaparinux. The main purpose of this study was to evaluate the accuracy of SF and D-dimer tests for DVT screening in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) treated with fondaparinux.. A total of 519 patients who underwent THA or TKA were evaluated. SF and D-dimer levels were evaluated on postoperative days 1, 4, 7, 14 and 21. DVT was confirmed by ultrasonography 4 days after surgery.. The incidence of DVT in patients treated with fondaparinux was significantly lower than in patients without fondaparinux. The SF test on postoperative day 1, and the D-dimer test on postoperative days 1, 4, and 7 were useful in untreated patients. However, in the patients treated with fondaparinux, the D-dimer test on postoperative day 7 only was useful for DVT screening.. The accuracy of SF and D-dimer test for the diagnosis of DVT was decreased by administration of fondaparinux. A new strategy for diagnosing DVT might be required for patients receiving fondaparinux.

Topics: Aged; Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fondaparinux; Humans; Male; Middle Aged; Polysaccharides; Postoperative Complications; Prospective Studies; Ultrasonography; Venous Thrombosis

Hereditary antithrombin (AT) deficiency is a rare autosomal disease. More than 200 mutations have been described in the AT gene leading to its deficiency. We describe here a case of type I AT deficiency in a 26-year-old Polish man who experienced proximal deep vein thrombosis and pulmonary embolism associated with a transient thrombotic risk factor, the right ankle trauma, despite the use of low-molecular-weight heparin prophylaxis. The family history was negative for venous thromboembolism. The AT activity was initially 47% and on repeated analysis 53%, and the antigen level, 0.15 g/l. The analysis of AT gene revealed the presence at the heterozygous state of a substitution G more than T located at the first nucleotide 3' of exon 3a (c.624 + 1 G > T, Human Genome Variation Society numbering system). The substitution might be detrimental taking account for its position in a donor splice site. To the best of our knowledge this mutation has not been previously described, so it was named antithrombin Krakow II.

Topics: Adult; Anticoagulants; Exons; Fibrin; Heparin, Low-Molecular-Weight; Heterozygote; Humans; Male; Mutation; Pulmonary Embolism; Venous Thrombosis; White People

The goal of this study was to develop and validate a new fibrin-targeted imaging agent that enables high-resolution near-infrared fluorescence (NIRF) imaging of deep vein thrombosis (DVT).. NIRF imaging of fibrin could enable highly sensitive and noninvasive molecular imaging of thrombosis syndromes in vivo.. A fibrin-targeted peptide was conjugated to a near-infrared fluorophore Cy7, termed FTP11-Cy7. The NIRF peptide is based on a fibrin-specific imaging agent that has completed Phase II clinical magnetic resonance imaging trials. In vitro binding of FTP11-Cy7 to human plasma clots was assessed by using fluorescence reflectance imaging. Next, FTP11-Cy7 was intravenously injected in mice with femoral DVT induced by topical 7.5% ferric chloride treatment. Intravital fluorescence microscopy and noninvasive fluorescence molecular tomography-computed tomography were performed in 32 mice with DVT, followed by histological analyses.. In vitro human clot-binding analyses showed a 6-fold higher NIRF clot target-to-background ratio (TBR) of FTP11-Cy7 than free Cy7 (6.3 ± 0.34 vs. 1.2 ± 0.03; p < 0.0001). The thrombus TBR of acute and subacute femoral DVT with FTP11-Cy7 obtained by using intravital fluorescence microscopy was >400% higher than control free Cy7. Binding of FTP11-Cy7 to thrombi was blocked by a 100-fold excess of unlabeled competitor peptide both in vitro and in vivo (p < 0.001 for each). Histological analyses confirmed that FTP11-Cy7 specifically accumulated in thrombi. Noninvasive fluorescence molecular tomography-computed tomography imaging of fibrin in jugular DVT demonstrated strong NIRF signal in thrombi compared with sham-operated jugular veins (mean TBR 3.5 ± 0.7 vs. 1.5 ± 0.3; p < 0.05).. The fibrin-targeted NIRF agent FTP11-Cy7 was shown to avidly and specifically bind human and murine thrombi, and enable sensitive, multimodal intravital and noninvasive NIRF molecular imaging detection of acute and subacute murine DVT in vivo.

Topics: Animals; Chlorides; Disease Models, Animal; Femoral Vein; Ferric Compounds; Fibrin; Fluorescent Dyes; Half-Life; Humans; Indoles; Injections, Intravenous; Mice; Mice, Inbred C57BL; Microscopy, Confocal; Microscopy, Fluorescence; Molecular Imaging; Oligopeptides; Phlebography; Radionuclide Imaging; Spectroscopy, Near-Infrared; Tissue Distribution; Tomography, X-Ray Computed; Venous Thrombosis

Topics: Animals; Femoral Vein; Fibrin; Fluorescent Dyes; Humans; Indoles; Microscopy, Confocal; Microscopy, Fluorescence; Molecular Imaging; Oligopeptides; Spectroscopy, Near-Infrared; Venous Thrombosis

We compared the antithrombotic effects in vivo of 2 chemically different carbon monoxide-releasing molecules (CORM-A1 and CORM-3) on arterial and venous thrombus formation and on hemostatic parameters such as platelet activation, coagulation, and fibrinolysis. The hypotensive response to CORMs and their effects on whole blood gas analysis and blood cell count were also examined.. CORM-A1 (10-30 µmol/kg, i.v.), in a dose-dependent fashion, significantly decreased weight of electrically induced thrombus in rats, whereas CORM-3 inhibited thrombosis only at the highest dose used (30 µmol/kg). CORM-A1 showed a direct and stronger inhibition of platelet aggregation than CORM-3 in healthy rats, both in vitro and in vivo. The antiaggregatory effect of CORM-A1, but not CORM-3, correlated positively with weight of the thrombus. Concentration of active plasminogen activator inhibitor-1 in plasma also decreased in response to CORM-A1, but not to CORM-3. Neither CORM-A1 nor CORM-3 had an effect on plasma concentration of active tissue plasminogen activator. CORM-3, but not CORM-A1, decreased the concentration of fibrinogen, fibrin generation, and prolonged prothrombin time. Similarly, laser-induced venous thrombosis observed intravitally via confocal system in green fluorescent protein mice was significantly decreased by CORMs. Although both CORM-A1 and CORM-3 (30 µmol/kg) decreased platelets accumulation in thrombus, only CORM-A1 (3-30 µmol/kg) inhibited platelet activation to phosphatidylserine on their surface.. CORM-3 and CORM-A1 inhibited thrombosis in vivo, however CORM-A1, which slowly releases carbon monoxide, and displayed a relatively weak hypotensive effect had a more pronounced antithrombotic effect associated with a stronger inhibition of platelet aggregation associated with a decrease in active plasminogen activator inhibitor-1 concentration. In contrast, the fast CO releaser CORM-3 that displayed a more pronounced hypotensive effect inhibited thrombosis primarily through a decrease in fibrin generation, but had no direct influence on platelet aggregation and fibrynolysis.

Topics: Animals; Arterial Occlusive Diseases; Blood Coagulation; Blood Gas Analysis; Blood Platelets; Blood Pressure; Boranes; Carbon Monoxide; Carbonates; Disease Models, Animal; Dose-Response Relationship, Drug; Fibrin; Fibrinogen; Fibrinolysis; Fibrinolytic Agents; Green Fluorescent Proteins; Injections, Intravenous; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Confocal; Organometallic Compounds; Plasminogen Activator Inhibitor 1; Platelet Aggregation; Prothrombin Time; Rats; Rats, Wistar; Solubility; Thrombosis; Time Factors; Venous Thrombosis; Water

Venous thrombus is subsequently organized and replaced by fibrous connective tissue. However, the sequential changes in venous thrombi are not reliably detected by current noninvasive diagnostic techniques. The purpose of this study is to reveal whether magnetic resonance (MR) can detect venous thrombus, define thrombus age and predict thrombolytic responses. Thrombus in the rabbit jugular vein was imaged with a 1.5-T MR system at 4 h and at 1, 2 and 4 weeks using three-dimensional (3D) fast asymmetric spin echo T2-weighted (T2W) and 3D-gradient echo T1-weighted (T1W) sequences. The jugular veins were histologically assessed at each time point. Magnetic resonance imaging (MRI) was also performed in vivo before and 30 min after tissue plasminogen activator (t-PA) administration. The thrombi in MRI were comparable in size to histological sections. The signal intensity (SI) of thrombi at 4 h was heterogeneously high or low on T2W or T1W images, respectively. The SI of thrombi on T2W images decreased time-dependently, but increased on T1W images at 1 and 2 weeks. Morphological analysis showed time-dependent decreases in erythrocyte, platelet and fibrin areas and time-dependent increases in smooth muscle cell, macrophage, collagen and iron areas. The t-PA administration significantly decreased thrombus volume at 4 h but not at 1, 2 and 4 weeks. Venous thrombosis can be reliably and noninvasively detected by MRI. Measurement of SI might support assessments of thrombus age and thrombolytic response.

Topics: Animals; Blood Platelets; Erythrocytes; Fibrin; Humans; Imaging, Three-Dimensional; Jugular Veins; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Male; Rabbits; Signal Processing, Computer-Assisted; Thrombosis; Time Factors; Tissue Plasminogen Activator; Venous Thrombosis

Topics: Adult; Antithrombin III; Antithrombin III Deficiency; Blood Coagulation; Codon, Nonsense; Female; Fibrin; Humans; Infant, Newborn; Male; Pedigree; Phenotype; Poland; Pregnancy; Thrombosis; Venous Thrombosis

Topics: C-Reactive Protein; Coronary Artery Disease; Female; Fenofibrate; Fibrin; Fibrinolysis; Heptanoic Acids; Homocysteine; Humans; Hypersensitivity, Immediate; Laser Coagulation; Lipoprotein(a); Male; Pyrroles; Retinal Vein; Retinal Vein Occlusion; Simvastatin; Tetrahydroisoquinolines; Thrombosis; Venous Thromboembolism; Venous Thrombosis

To test whether T(1)-weighted MRI can detect the differences in the rate of thrombolysis induced by recombinant tissue plasminogen activator (rt-PA) between platelet-rich regions and red blood cell (RBC)-rich regions of venous thrombi ex vivo.. Each of 21 venous thrombi ex vivo (8 pulmonary emboli and 13 in situ thrombi) was dissected along the longitudinal axis. Half of it was analyzed for the presence of platelet, fibrin, and RBC components by immunohistochemistry and the other half was imaged serially by high-resolution T(1)-weighted three-dimensional MRI to assess the progression of thrombolysis. The MR images were analyzed for proportions of the remaining platelet-rich and RBC-rich regions.. Laminated platelet-rich regions, corresponding to Zahn lines, were confirmed immunohistochemically and by MRI in 18/21 venous thrombi. In T(1)-weighted MR images (TE/TR = 10/105 ms) the mean signal intensity of platelet-rich regions was on average 2.3 higher than that of RBC-rich regions. The rate of thrombolysis in platelet-rich regions was on average 30% lower than in RBC-rich regions. After 120 min of thrombolysis the proportion of lysed platelet-rich regions was 0.27 ± 0.04 versus 0.40 ± 0.08 in RBC regions, which resulted in 1.4% decrease of lysed thrombus volume per 1% increase of platelet-rich content.. Venous thrombi are most often composed of interspersed platelet-rich and RBC-rich regions. T(1) -weighted MRI is capable of noninvasive discrimination between those two components of venous thrombi ex vivo which have a different susceptibility to thrombolysis by rt-PA.

Topics: Blood Platelets; Erythrocytes; Fibrin; Humans; Immunohistochemistry; Longitudinal Studies; Magnetic Resonance Imaging; Plasminogen Activators; Recombinant Proteins; Thrombolytic Therapy; Thrombosis; Venous Thrombosis

To investigate the clinical phenotype, genotype and molecular mechanism of recurrent venous thrombosis in two Chinese pedigrees with type I antithrombin (AT) deficiency.. The routine coagulation screening tests were detected, thrombin generation tests was performed to evaluate the hypercoagulation. Anticardiolipin antibody (ACA) and lupus anticoagulant (LA) were detected with enzyme-linked immunosorbent assay (ELISA) and diluted viper venom time assay (DVVT), respectively. The activities of protein C, protein S and AT (PC:A, PS:A, AT:A) were tested with chromogenic substrate assay or clotting method. The antigen of AT (AT:Ag) was performed with immunoturbidimetry methods. Western blot was used to analyze the molecular weight (MW) and the plasma levels of AT:Ag. All 7 exons and the flanking sequences were amplified by PCR. The mutation of AT gene and thrombophilia associated gene polymorphisms were analyzed by direct DNA sequencing. The expression plasmid of Ala404Asp mutant was constructed with site-directed mutagenesis method based on the wild-type (WT) AT cDNA contained in pcDNA 3.1 vector, and transiently expression of AT WT and the Ala404Asp mutant was performed using HEK293T cells. Cultured supernatant and cell lysates were collected and measured for AT:Ag by ELISA and Western blot.. The results of routine coagulation tests in two probands were normal, thrombin generation tests indicated that proband 1 presented hypercoagulable state with 2.8 and 1.5 times higher of the endogenous thrombin potential (ETP) and peak height compared with that of normal, respectively. The levels of PC:A, PS:A, ACA and LA were normal. AT:A in proband 1 and proband 2 were 45% and 32%, and AT:Ag were almost half of the normal (121 mg/L and 158 mg/L), respectively. The results of Western blot showed that both probands' plasma levels of AT:Ag were lower than the normal pooled plasma and MW was normal. Two heterozygous mutations of g.3291C→T(Thr98Ile), g.13863C > A(Ala404Asp) were identified in the probands, respectively. No proband had venous thrombosis associated gene polymorphisms. Expression in vitro showed that AT:Ag in culture media and lysates of Ala404Asp are 4.8% and 60.6% of that of WT, respectively.. Thr98Ile and Ala404Asp mutation of AT gene significantly correlate with recurrent venous thrombosis in the two probands, respectively. Ala404Asp has not been described before. The mutant Ala404Asp protein can not be expressed due to impaired secretion and increased intracellular degradation, resulting in type I AT deficiency.

Topics: Adult; DNA Mutational Analysis; Female; Fibrin; Humans; Middle Aged; Mutation; Pedigree; Phenotype; Venous Thrombosis

Most patients with malignant diseases are frequently complicated with some type of thrombosis, such as disseminated intravascular coagulation (DIC) or deep vein thrombosis (DVT)/pulmonary embolism (PE).. The cohort and retrospective study was designed to examine the frequency of thrombosis in patients with malignant diseases and to evaluate the efficacy of D-dimer and soluble fibrin (SF) for the diagnosis of thrombosis.. The plasma concentrations of D-dimer and SF were measured in patients with malignant diseases suspected of having thrombosis. D-dimer and SF were measured using a latex aggregation assay.. Thrombosis was observed in 23.3% of the patients with malignant diseases. Disseminated intravascular coagulation was frequently observed in patients with hepatoma, and DVT/PE was frequently observed in patients with colon cancer, lung cancer, and uterine cancer. The plasma levels of D-dimer and SF were increased in malignant diseases, especially hepatoma. Plasma levels of D-dimer and SF were significantly higher in patients with thrombosis in comparison to patients without thrombosis. A receiver operating characteristic (ROC) analysis showed the D-dimer and SF levels to be useful in the diagnosis of thrombosis.. Elevated D-dimer and SF levels might indicate a high risk of thrombosis in patients with malignant disease; however, these assays still need to be standardized.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Cohort Studies; Disseminated Intravascular Coagulation; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Neoplasms; Predictive Value of Tests; Pulmonary Embolism; Retrospective Studies; ROC Curve; Thrombophilia; Venous Thrombosis; Young Adult

Soluble fibrin (SF) and D-dimer are useful for making the diagnosis of deep vein thrombosis (DVT). However, the evidence for using such markers and optimal timing to diagnose postoperative DVT are unclear. We evaluate the usefulness of SF and D-dimer testing for the diagnosis of postoperative DVT. A total of 207 patients who had total hip arthroplasty or knee arthroplasty were evaluated. SF and D-dimer were tested on postoperative days 1 and 7. DVT was confirmed with ultrasonography. SF level on postoperative day 1 was the most useful, although D-dimer evaluation on postoperative days 1 and 7 was also useful. Using a SF cut-off of more than 4.00 microg ml(-1), the sensitivity was 90%, the specificity was 33%. Although the SF and D-dimer tests cannot be used as stand-alone tests, SF and D-dimer are valuable screening tools. We recommend two-stage screening including first with the SF or D-dimer test, followed by ultrasonography or venography.

Topics: Aged; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Postoperative Complications; Sensitivity and Specificity; Solubility; Ultrasonography; Venous Thrombosis

Although the incidence of pediatric thrombosis has increased over the last decade, noncatheter-related deep venous thrombosis (nCDVT) is rare in children. Congenital and acquired hypercoagulable states may play an important role in the pathogenesis of nCDVT. In this study, we evaluated fibrinolytic parameters by measuring individual concentrations of fibrinolytic proteins and by tissue factor initiated whole blood thromboelastography (TEG), in which a fibrin clot was lyzed by exogenously added tissue plasminogen activator (tPA). Children with nCDVT were compared with age and sex-matched controls. TAFI concentrations were significantly higher in the patient group but there was no difference in the PAI-1, tPA and lipoprotein (a) concentrations. Significantly decreased fibrinolysis was found on TEG in the patient group suggesting that hypofibrinolysis may play an important role in the pathogenesis of nCDVT in children. To our knowledge, this is the first pediatric study that has systematically evaluated the role of fibrinolysis in the pathogenesis of DVT. Given our results, the role of fibrinolysis in the pathogenesis of nCDVT in children should be further evaluated in larger studies.

Topics: Adolescent; Adult; Age Factors; Child; Child, Preschool; Cohort Studies; Female; Fibrin; Fibrinolysis; Humans; Male; Racial Groups; Sex Factors; Thrombelastography; Tissue Plasminogen Activator; Venous Thrombosis; Young Adult

The generation of thrombin is a critical process in the formation of venous thrombi. In isolated plasma under static conditions, phosphatidylserine (PS)-exposing platelets support coagulation factor activation and thrombin generation; however, their role in supporting coagulation factor binding under shear conditions remains unclear. We sought to determine where activated factor X (FXa), (pro)thrombin, and fibrin(ogen) are localized in thrombi formed under venous shear.. Fluorescence microscopy was used to study the accumulation of platelets, FXa, (pro)thrombin, and fibrin(ogen) in thrombi formed in vitro and in vivo. Co-perfusion of human blood with tissue factor resulted in formation of visible fibrin at low, but not at high shear rate. At low shear, platelets demonstrated increased Ca(2+) signaling and PS exposure, and supported binding of FXa and prothrombin. However, once cleaved, (pro)thrombin was observed on fibrin fibers, covering the whole thrombus. In vivo, wild-type mice were injected with fluorescently labeled coagulation factors and venous thrombus formation was monitored in mesenteric veins treated with FeCl(3). Thrombi formed in vivo consisted of platelet aggregates, focal spots of platelets binding FXa, and large areas binding (pro)thrombin and fibrin(ogen).. FXa bound in a punctate manner to thrombi under shear, while thrombin and fibrin(ogen) distributed ubiquitously over platelet-fibrin thrombi. During thrombus formation under venous shear, thrombin may relocate from focal sites of formation (on FXa-binding platelets) to dispersed sites of action (on fibrin fibers).

Topics: Animals; Blood Platelets; Calcium Signaling; Factor Xa; Fibrin; Fibrinogen; Humans; Mice; Perfusion; Phosphatidylserines; Platelet Aggregation; Protein Binding; Thrombin; Thromboplastin; Venous Thrombosis

Soluble fibrin (SF) and D-dimer are considered to be useful for the diagnosis of thrombosis; however, the efficacy of the diagnosis of deep vein thrombosis (DVT) after orthopaedic surgery by SF and D-dimer is still not well established. The present study was designed to evaluate the efficacy of SF and D-dimer in the diagnosis of DVT after orthopaedic surgery. The plasma concentrations of SF and D-dimer were measured in 99 patients following orthopaedic surgery. The plasma concentrations of D-dimer and SF in patients undergoing orthopaedic surgery were markedly high in comparison to healthy volunteers, and these markers were increased after surgery. The plasma concentrations of D-dimer were significantly higher in patients with DVT than in those without DVT at days 4, 7, 10 and 14, and those of SF were significantly higher in patients with DVT than in those without DVT at days 1, 4 and 14. A receiver operating characteristic (ROC) analysis of SF and D-dimer for diagnosis of DVT after surgery generated an ROC curve that showed SF to be better than D-dimer at day 1, while D-dimer was better than SF at day 4. In addition, less than 7.2 microg/ml of D-dimer or 3.6 microg/ml of SF at day 1 after surgery, or less than 7.0 microg/ml of D-dimer at day 4 excluded DVT. These findings suggest that the D-dimer and SF are useful for the diagnosis and exclusion of DVT after orthopaedic surgery.

Topics: Aged; Case-Control Studies; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Orthopedic Procedures; Postoperative Complications; ROC Curve; Venous Thrombosis

Thrombus growth under low blood flow velocity plays an important role in the development of deep venous thrombosis (DVT). Increased plasma levels and activities of coagulation factor VIII (FVIII) comprise risk factors for DVT and pulmonary thromboembolism.. To localize FVIII in human venous thrombi of DVT and to determine whether FVIII contributes to thrombus formation under low shear conditions.. The localization of FVIII in venous thrombi obtained from patients with DVT was examined by immunohistochemistry. The role of FVIII in thrombus formation was investigated using a flow chamber system. Venous blood from healthy volunteers were incubated with an anti-FVIII monoclonal antibody (VIII-3776) or non-immunized mouse IgG(1). Blood samples were perfused on immobilized type III collagen at wall shear rates of 70/s and 400/s and then the surface area covered by platelets and fibrin was morphometrically evaluated. Prothrombin fragment 1+2 (PF1+2) generation was measured before and after perfusion.. Venous thrombi of DVT comprised a mixture of platelets, fibrin and erythrocytes. Factor VIII appeared to be colocalized with glycoprotein IIb/IIIa, fibrin and von Willebrand factor in the thrombi. VIII-3776 specifically recognized the light chain of FVIII and prolonged the activated partial thromboplastin time (aPTT), but not prothrombin time (PT). The antibody significantly reduced platelets and fibrin covering, as well as PF1+2 generation at wall shear rates of 70/s and 400/s.. These results suggest that FVIII contributes to platelet aggregation and fibrin formation via thrombin generation under low shear conditions.

Topics: Adult; Aged; Animals; Blood Platelets; Collagen; Electrophoresis, Polyacrylamide Gel; Factor VIII; Female; Fibrin; Fluorescent Antibody Technique; Humans; Mice; Mice, Inbred BALB C; Mice, Inbred MRL lpr; Middle Aged; Platelet Aggregation; Shear Strength; Thrombin; Venous Thrombosis; von Willebrand Factor

Emerging lines of evidence have suggested that certain dysfibrinogens present a significant risk of thrombosis.. The thrombophilic nature of a new-type of dysfibrinogen Kagoshima identified in a 36-year-old female with deep vein thrombosis during the postpartum period was studied.. Based on the analyses of the patient fibrinogen and the fibrinogen genes, fibrinogen Kagoshima was shown to have the amino acid substitution of gammaThr-314 to Ile that resulted in impaired function and hypofibrinogenemia. Polymerization of fibrin monomers derived from patient fibrinogen was severely impaired with a partial correction in the presence of calcium ions, causing very low clottability and delayed cross-linking of patient fibrin catalyzed by activated factor XIII. Because of the low clottability, a large amount of soluble fibrin was formed upon thrombin treatment, resulting in an increase of thrombin in the soluble fraction. Additionally, tPA-mediated plasmin generation on fibrin was impaired and calcium-ion-dependent integrity of the gamma-chain D domain of Kagoshima fibrinogen was perturbed. The presence of many tapered-fiber ends inside the tangled fibrin networks, observed by scanning electron microscopy, suggested early termination of fibrin polymerization and the structural alteration.. These data suggest that fibrinogen Kagoshima is dysfunctional, giving rise to formation of fibrinolysis-resistant soluble fibrin polymers and entrance of soluble fibrin associating with thrombin to the circulation, partly accounting for the thrombophilic nature of the affected fibrinogen and fibrin molecules.

Topics: Adult; Amino Acid Substitution; Calcium; Catalysis; Electrophoresis, Polyacrylamide Gel; Female; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Fibrinolysin; Humans; Ions; Microscopy, Electron, Scanning; Polymerase Chain Reaction; Postpartum Period; Solubility; Surface Properties; Thrombin; Thrombophilia; Time Factors; Tissue Plasminogen Activator; Venous Thrombosis

Routinely available coagulation assays are not capable of detecting clinically defined hypercoagulable states. A number of global coagulation assays have been developed with the potential to evaluate hypercoagulability, which predisposes to the common clinical events of arterial and venous thromboembolism (VTE).. We hypothesized that the overall hemostatic potential (OHP) assay would show abnormal fibrin generation and lysis in patients with clinically defined hypercoagulable states.. We used the OHP assay as described by Blombäck and colleagues [1,2] in 161 clinically hypercoagulable patients with arterial or VTE, pregnancy complications or autoimmune disease. Eighty patients had associated antiphospholipid antibodies (APLA). Ninety-eight normal plasma donors were tested for comparison.. We derived three new assay parameters for correlation with hypercoagulable states: the maximum optical density, maximum slope, and delay in onset of fibrin generation. We found significantly different assay results for all patients' parameters examined when compared with controls, indicating both increased fibrin generation and reduced fibrinolysis in hypercoagulable patients. The findings were similar whether samples were collected in association with an acute thrombotic event or not. Estimated assay sensitivity for detection of a clinically defined hypercoagulable state was 96%.. The OHP assay is a simple, inexpensive global test that is useful for assessing patients with hypercoagulable states including APLA. OHP results are significantly abnormal in hypercoagulable groups compared with controls, indicating that both increased fibrin generation and reduced fibrinolysis contribute to hypercoagulable states. The assay may ultimately assist in tailoring clinical management to patients' individual requirements.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antiphospholipid Syndrome; Blood Coagulation Tests; Case-Control Studies; Female; Fibrin; Fibrinolysis; Hemostasis; Humans; Male; Middle Aged; Pilot Projects; Predictive Value of Tests; Pregnancy; Pregnancy Complications, Hematologic; Reproducibility of Results; Sensitivity and Specificity; Thromboembolism; Thrombophilia; Time Factors; Venous Thrombosis

Topics: Factor V; Family Health; Female; Fibrin; Genetic Predisposition to Disease; Humans; Male; Prothrombin; Risk Factors; Spain; Thrombophilia; Venous Thrombosis

Topics: Anticoagulants; Drug Administration Schedule; Factor Xa Inhibitors; Female; Fibrin; Fondaparinux; Humans; Middle Aged; Perioperative Care; Phenprocoumon; Polysaccharides; Postoperative Hemorrhage; Surgical Procedures, Operative; Thromboembolism; Thrombophilia; Venous Thrombosis; Vitamin K

In previous studies, (99m)Tc-recombinant tissue plasminogen activator (rt-PA) imaging has had a high sensitivity and specificity for the detection of deep vein thrombosis (DVT). In this technique, the plasminogen activation site of rt-PA undergoes inactivation but fibrin binding is retained. Uptake of (99m)Tc-rt-PA into DVT relies on binding of C-terminal lysine residues on fibrin. It is postulated that as the thrombus ages, fewer fibrin sites are available for (99m)Tc-rt-PA and that there should be a progressive decrease in (99m)Tc-rt-PA uptake in old thrombi as compared with fresh thrombi. The ability to differentiate fresh from old thrombus would have significant clinical implications in the objective diagnosis of recurrent DVT. Our aim was to examine the relative uptake of (99m)Tc-rt-PA in acute DVT over the first 30 d after diagnosis.. Seventy-four patients with acute symptomatic DVT were entered into the study. Patients underwent ultrasound and (99m)Tc-rt-PA imaging on days 1, 7, and 30.. Residual thrombus was detected by ultrasonography in 46 (84%) of 55 patients on day 7 and in 29 (66%) of 44 patients on day 30. Of the persisting thrombi on day 7, 72% (33/46) showed (99m)Tc-rt-PA uptake. Of the persisting thrombi on day 30, 0% (0/29) showed (99m)Tc-rt-PA uptake.. Uptake of (99m)Tc-rt-PA into DVT was absent 30 d after diagnosis. This finding suggests that this imaging technique can distinguish fresh from old thrombus.

Topics: Acute Disease; Female; Fibrin; Humans; Leg; Male; Middle Aged; Mucoproteins; Plasminogen Activators; Protein Binding; Radionuclide Imaging; Radiopharmaceuticals; Recombinant Proteins; Recurrence; Technetium; Thigh; Time Factors; Ultrasonography; Veins; Venous Thrombosis

The recombinant protein SAK-RGD-K2-Hir is characterized by its fibrin-specific properties of plasminogen activation combined with antithrombin and antiplatelet activities. It was previously shown in our in-vitro studies to be a more potent and faster-acting thrombolytic agent compared with standard r-SAK. In order to document the effects of the thrombolytic potential of SAK-RGD-K2-Hir we examined this protein in an electrically induced carotid artery thrombosis model and stasis-induced venous model in rats. In the arterial thrombosis model, a bolus injection of SAK-RGD-K2-Hir was less effective than rt-PA and r-SAK. However, the most effective in the improvement and maintenance of carotid patency and in arterial thrombus mass reduction was SAK-RGD-K2. In contrast, all r-SAK derivatives reduced venous thrombus weight significantly in comparison to r-SAK and r-Hir. However, the most observable decrease in thrombus weight was obtained after application of recombinant proteins containing the r-Hir. The bleeding time was significantly prolonged in the animals treated with proteins containing r-Hir at a dose of 1.0 mg/kg. There were no observable changes in plasma fibrinogen concentration. In conclusion, our findings show thrombolytic activity in intravenous bolus injection of the novel thrombolytic agent SAK-RGD-K2-Hir in rats. Although this protein compares favourably with r-SAK in rat venous thrombolysis, we were unable to confirm the beneficial effects of SAK-RGD-K2-Hir over r-SAK and rt-PA in the carotid artery thrombolysis model. Furthermore, our results also suggest that SAK-RGD-K2-Hir bears a risk of bleeding, but this may be true for higher doses.

Topics: Animals; Bleeding Time; Blood Coagulation; Carotid Artery Thrombosis; Disease Models, Animal; Dose-Response Relationship, Drug; Electric Stimulation; Fibrin; Fibrinolytic Agents; Hemorrhage; Hirudins; Ligation; Male; Metalloendopeptidases; Partial Thromboplastin Time; Rats; Rats, Wistar; Recombinant Fusion Proteins; Thrombin Time; Time Factors; Tissue Plasminogen Activator; Vascular Patency; Venae Cavae; Venous Thrombosis

A pentapeptide, Gly-Pro-Arg-Pro-Pro, with high affinity for alpha-chain-fibrin was labeled with (99m)Tc ((99m)Tc-TP850) and evaluated in swine to image experimental venous thromboembolism (deep vein thrombosis [DVT]) and pulmonary embolism (PE).. Scatchard analysis was performed to determine fibrin affinity for TP850 and the number of binding sites (receptors) per milligram of fibrin. DVT was induced in the left jugular vein and PE was induced by introducing a preformed autologous blood clot into the right atrium using a 7-French introducer sheath inserted into the right jugular vein. (99m)Tc-TP850 was injected at 4, 24, 48, 72, 96, or 120 h later. Animals were imaged for up to 4 h after injection, heparinized, and sacrificed. Lungs were extirpated, radiographed, and imaged, and the PE was removed. Other tissues, including blood and normal lungs, were harvested and, concomitantly, (99m)Tc was counted for determination of target-to-tissue ratios and the percentage injected dose per gram of tissue.. The affinity for human fibrin was 10(-9) mol/L and there were >10(15) receptors per milligram of fibrin. DVT and PE were visualized for up to 4 h after injection with high DVT/blood (7.9-22.6), DVT/muscle (31.1-89.4), PE/blood (1-155), and PE/lung (0.8-245) ratios. Thereafter, the PEs fragmented spontaneously below the spatial resolution of the gamma-camera and, despite the high associated radioactivity, could not be localized in vivo. The fragmented clots were detectable by scintigraphy on excised lungs and provided excellent concordance with radiograms.. (99m)Tc-TP850 with its modest affinity (10(-9) mol/L), rapid blood clearance, and high DVT and PE uptake is a promising agent for imaging vascular thrombosis.

Topics: Animals; Fibrin; Metabolic Clearance Rate; Oligopeptides; Organ Specificity; Organotechnetium Compounds; Pulmonary Embolism; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Swine; Tissue Distribution; Venous Thrombosis

Fibrin-related markers such as soluble fibrin (SF) and D-dimer are considered useful for the diagnosis of thrombosis. However, the evidence for diagnosis of thrombosis by fibrin-related markers is not well-established.. To evaluate the cutoff values of D-dimer and SF in the diagnosis of thrombosis.. Plasma concentrations of SF and D-dimer were measured in 784 inpatients suspected of having thrombosis between 1 August 2003 and 31 December 2004, and then correlated with thrombosis.. Plasma concentrations of D-dimer and SF were significantly higher in patients with disseminated intravascular coagulation (DIC), deep vein thrombosis (DVT) and cerebral thrombosis, compared with those in patients without thrombosis. When cutoff values of > 3.0 microg mL(-1) for D-dimer and > 6.0 microg mL(-1) for SF were used for the diagnosis, more than 50% of patients (with the exception of liver transplant patients and postoperative patients) had thrombosis. Receiver operating characteristic analysis showed that SF was more useful than D-dimer for the diagnosis of thrombosis (i.e. DVT and DIC). The cutoff value of D-dimer (7.87 microg mL(-1)) was the same for DVT and DIC, while that of SF was slightly lower for DVT (7.05 microg mL(-1)) than for DIC (8.60 microg mL(-1)). Our findings suggest that high levels of plasma fibrin-related markers reflect high risk for thrombosis.

Topics: Aged; Biomarkers; Bone Diseases; Communicable Diseases; Disseminated Intravascular Coagulation; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Intracranial Thrombosis; Male; Middle Aged; Neoplasms; Risk Factors; ROC Curve; Venous Thrombosis

Stenting has become a common intervention for venous occlusive disease. Little is known regarding the composition of venous thrombi complicating stent placement. The optimal design of antithrombotic agents in this setting requires this knowledge. Quantitative immunohistochemistry was undertaken to define the platelet, fibrin(ogen) and leukocyte composition and spatial orientation of venous thrombi following percutaneous iliac stent placement in pigs. Venous stent thrombus size was measured by weight and scintillation detection of autologous (111) In-platelets. Thrombi were divided in segments (cephalad to caudad), sectioned and stained with monoclonal anti-platelet glycoprotein Ib or polyclonal anti-fibrin(ogen) fluorescent antibodies. Thrombus platelet content was 100-fold greater than paired whole blood samples. The caudal-most segments contained platelet-rich aggregates (p < 0.05) with abundant leukocytes (p < 0.0001) relative to more cephalad segments. Platelet and fibrin(ogen) content varied over an eight-fold range between segments but were directly correlated with each other (r = 0.77; p < 0.0001). The platelet co-localization with fibrin(ogen) is consistent with the phospholipid dependence of prothrombin activation. The abundance and caudal distribution of platelet-leukocyte aggregates indicate their preferential accretion from flowing blood early in the genesis of venous stent thrombi. These may represent novel cellular targets for the prevention and treatment of venous thrombosis.

Topics: Animals; Blood Platelets; Cell Adhesion; Cell Count; Fibrin; Iliac Vein; Immunohistochemistry; Leukocytes; Models, Animal; Stents; Swine; Venous Thrombosis

Deep venous thrombosis and pulmonary thromboembolism are common within weeks of spinal cord injury (SCI) but clinically uncommon in the chronically paralyzed. Fibrinogen half-life (FHL) and fibrin uptake of the legs (FUT), as indicators of an active thrombotic process, have been used to test this clinical impression.. Data from the use of autologous preparations of radioiodinated fibrinogen to determine FHL and FUT in 17 men paralyzed at cervical (6), thoracic (10), and lumbar levels (1), at ASIA grades A (15) and C (2) in 1974 to 1976 were reviewed. Group A consisted of 12 subjects 29 +/- 8 years of age and paralyzed 1 week to 5 months (median, 1 month). Group B consisted of 5 subjects 46 +/- 17 years of age and paralyzed 24 to 96 months (median, 36 months). Group B subjects were older and paralyzed longer than Group A. Group C consisted of 4 able-bodied control subjects enrolled at the same time for FHL studies, and these subjects were 34 to 38 years of age.. FHL was 61 +/- 14 hours for all SCI subjects and 95 +/- 23 hours for Group C (P = 0.001). Group A FHL was 59 +/- 16 hours, and FUT was positive in 8 of 12 subjects. Group B FHL was 66 +/- 7 hours, and FUT was positive in 3 of 4 subjects (1 FUT not done; P = 0.30 and 1.0, respectively).. Fibrinogen metabolism was abnormal in patients with acute SCI at high risk for pulmonary thromboembolism (PE) but continued to be abnormal beyond the high risk period for PE, possibly because of the greater age of the patients in the long-term paralysis group.

Topics: Acute Disease; Adult; Case-Control Studies; Chronic Disease; Disease Progression; Fibrin; Fibrinogen; Half-Life; Humans; Iodine Radioisotopes; Male; Middle Aged; Paralysis; Pulmonary Embolism; Risk Factors; Spinal Cord Injuries; Time Factors; Venous Thrombosis

The article contains data on venous thrombosis (VT) recurrence rate in patients with the first episode of thrombus formation after the completion of one-year therapy with warfarin. The investigation included study of the prognostic value of intravascular coagulation marker (thrombus precursor protein --TPP) for the risk of venous retrombosis. The study showed that a high TPP level at the end of standard therapy course with warfarin in patients who had the first episode of spontaneous venous thrombosis is a significant indicator of a possible thrombosis recurrence during the nearest two tears after treatment with anticoagulants.

Topics: Adult; Anticoagulants; Biomarkers; Enzyme-Linked Immunosorbent Assay; Female; Fibrin; Follow-Up Studies; Humans; Male; Prognosis; Prospective Studies; Risk Factors; Secondary Prevention; Venous Thrombosis; Warfarin

Plasma levels of granulocyte-derived elastase (GE-XDP), D-dimer and soluble fibrin (SF) were examined in 53 patients with deep vein thrombosis (DVT) and in 100 healthy volunteers. The mean plasma level of D-dimer was 0.92+/-0.81 microg/ml (+/-S.D.) in healthy volunteers and the mean+2 S.D. value (cutoff value for DVT) was 2.53 microg/ml, which was higher than that used in Europe and North America. Plasma levels of GE-XDP, D-dimer and SF were significantly higher in patients with DVT than in healthy volunteers, and diminished after 1 week of treatment with heparin, urokinase or tissue type plasminogen activator, though were still higher than those of the control subjects. The sensitivity of GE-XDP, D-dimer and SF for DVT was 81.1%, 75.5% and 79.2%, respectively. GE-XDP levels correlated with those of D-dimer and SF. Our results indicate that GE-XDP is a potentially useful marker for the diagnosis of DVT, suggesting that granulocytes are activated in patients with DVT. In our system, the cutoff value of D-dimer for the diagnosis of DVT is higher than in western countries, probably due to the use of different analytical assays.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Case-Control Studies; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Heparin; Humans; Leukocyte Elastase; Male; Middle Aged; Tissue Plasminogen Activator; Urokinase-Type Plasminogen Activator; Venous Thrombosis

There is an increased number of in vitro evidence that angiotensin II (Ang II) may promote thrombosis. However there are no in vivo experiments exploring the effect of Ang II on thrombus formation. In the present study we have investigated the influence of Ang II on venous thrombosis in renovascular hypertensive rats. Furthermore, we examined the role of AT(1) receptor and Ang II metabolites: angiotensin III (Ang III) and angiotensin IV (Ang IV) in the mechanisms of Ang II action. The contribution of coagulation and fibrinolytic systems in the mode of Ang II action was also determined. Venous thrombosis was induced by ligation of vena cava. Ang II infused into rats developing venous thrombosis caused dose-dependent increase in thrombus weight, which was partially reversed by losartan, selective AT(1) antagonist. Ang III did not influence the thrombus formation in hypertensive rats, while Ang IV caused a marked increase in thrombus weight only in one of the used doses. Our study shows that Ang II via AT(1) receptor enhances thrombosis development. The prothrombotic effect of Ang II may partially depend on enhanced leukocytes adhesion to endothelial cells accompanied by accelerated fibrin formation and increased plasma level of PAI-1. Moreover, Ang II action is partially mediated by one of its metabolites - Ang IV.

Topics: alpha-2-Antiplasmin; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin III; Animals; Blood Pressure; Carotid Arteries; Fibrin; Heart Rate; Hypertension, Renovascular; Infusions, Intravenous; Losartan; Male; Plasminogen Activator Inhibitor 1; Rats; Rats, Wistar; Receptor, Angiotensin, Type 1; Recombinant Proteins; Regional Blood Flow; Tissue Plasminogen Activator; Venous Thrombosis

The present study was designed to determine the cutoff values of D-dimer and soluble fibrin (SF) for the diagnosis of deep venous thrombosis (DVT) and pulmonary embolism (PE) in Japanese patients. Plasma levels of these molecules were measured in 243 patients suspected of having DVT and 100 healthy volunteers (controls). Out of 243 patients, 20 patients were diagnosed with DVT. In the control group, plasma levels of D-dimer and SF did not show normal distribution, and the 95% confidence intervals (CI) of D-dimer and SF were 2.45 microg/mL and 6.92 microg/mL, respectively. Plasma levels of D-dimer and SF of patients with DVT were significantly higher than of those without DVT. In patients with DVT, the minimum values of D-dimer and SF were 1.71 and 1.44 microg/mL, respectively. When the cutoff value was set at the average+1 SD of those of the control (D-dimer, about 1.8 microg/mL; SF, about 1.4 microg/mL), 1 and 0 patient with DVT was overlooked, respectively. The sensitivity and specificity of D-dimer and SF for DVT were 95% and 100%, and 61.9% and 53.8%, respectively. When the cutoff value was set at 95% CI of the control (D-dimer, 2.5 microg/mL; SF, 6.9 microg/mL), 2 and 9 patients with DVT were overlooked, respectively. The sensitivity and specificity of D-dimer and SF were 90% and 50%, and 77.6% and 88.3%, respectively. When the cutoff values set at 2.5 microg/mL of D-dimer or 6.9 microg/mL of SF, 1 DVT patient was overlooked, with sensitivity and specificity of 95% and 69.5%. Our data suggest that both D-dimer and SF are useful markers for the diagnosis of DVT and that measurement of both D-dimer and SF increases the sensitivity and specificity for the diagnosis of DVT/PE.

Topics: Angiography; Data Interpretation, Statistical; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Male; Middle Aged; Predictive Value of Tests; Pulmonary Embolism; Ultrasonography, Doppler; Venous Thrombosis

We assessed three soluble fibrin monomer (SFM) assays in 231 in and out-patients with clinically suspected deep-vein thrombosis. Thrombosis was confirmed or excluded by complete lower-limb ultrasound. SFM assay were less accurate than VIDAS D-dimer and in patients with small thrombosis or under anticoagulation. Specificity was lower for a similar sensitivity.

Topics: Diagnostic Techniques, Cardiovascular; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Lower Extremity; Venous Thrombosis

To determine the role of CXCR2, the receptor for cysteine-X-cysteine (CXC) chemokines, and its primary effector cell, the neutrophil (PMN), on deep venous thrombosis (DVT) resolution.. DVT in BALB/c, anti-CXCR2 antibody-treated, and BALB/c CXCR2(-/-) mice were created by infrarenal inferior vena cava (IVC) ligation and the thrombus harvested at various time points over 21 days. The CXCR2(-/-) mice had significantly larger thrombi at early time points (days 2 to 8), and significantly decreased intrathrombus PMNs, monocytes, and neovascularization as compared with controls. Thrombus KC/CXCL1 was significantly higher at 2 days in CXCR2-/- thrombi as measured by enzyme-linked immunosorbent assay. Fibrin content was significantly higher, with less uPA gene expression at 4 days in CXCR2-/- thrombi. Late fibrotic maturation of the thrombus was delayed in the CXCR2-/- mice, with significantly decreased 8 day MMP-2 activity, whereas MMP-9 activity was elevated as compared with controls. Similar impairment in DVT resolution was found at 8 days with anti-CXCR2 inhibition. However, systemic neutropenia, unlike CXCR2 deletion, did not increase the thrombus size as compared with controls.. Normal DVT resolution involves CXCR2-mediated neovascularization, collagen turnover, and fibrinolysis, and it is probably primarily monocyte-dependent.

Topics: Animals; Cells, Cultured; Chemokine CXCL1; Chemokines, CXC; Chemotaxis; Collagen; Endothelial Cells; Fibrin; Fibroblast Growth Factor 2; Humans; Intercellular Signaling Peptides and Proteins; Laminin; Ligation; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mice; Mice, Inbred BALB C; Mice, Knockout; Models, Animal; Monocytes; Neovascularization, Pathologic; Neutropenia; Neutrophils; Receptors, Interleukin-8B; Vascular Endothelial Growth Factor A; Vena Cava, Inferior; Venous Thrombosis

Topics: Catheterization, Central Venous; Constriction, Pathologic; Drug-Related Side Effects and Adverse Reactions; Fibrin; Humans; Peripheral Vascular Diseases; Prognosis; Vena Cava, Superior; Venous Thrombosis

To determine the incidence of pericatheter sleeve formation, thrombus formation, and stenosis of the central veins in hemodialysis patients with temporary catheters.. In this prospective study, 57 patients (40 males, 17 females) with temporary dialysis catheters had catheter venography by pulling back the catheter just before removal. Patient's age range was 25-87 years (mean age, 51 years). The venographic studies were evaluated for pericatheter sleeve formation, thrombus formation, and stenosis of the brachiocephalic vein (BCV) and the superior vena cava (SVC). The IJV could only be evaluated if there was adequate filling during contrast administration. In a subgroup of patients who had had only right IJV or only right SCV catheters, impact of these catheters on the central veins was compared.. The catheter location was right internal jugular vein (IJV) in 26 cases, right subclavian vein (SCV) in 27 cases, left IJV in 1 case, and left SCV in 3 cases. Thirty-two patients (56%) had had only one temporary catheter and the rest had had more than one inserted. The mean dwell time for the catheters was 21 days (range 7-59 days). A pericatheter sleeve was detected on venography in 32 (56%) patients and thrombus formation was noted in 16 patients (28%). A total of 41 patients (72%) exhibited pericatheter sleeve and/or thrombus formation. While 19 of the 32 patients (59%) without previous catheterization had a sleeve around the catheter, only 13 (52%) of 25 patients who had had multiple catheters inserted had a sleeve (P > 0.005). Of the eight patients (14%) with BCV stenosis, two had >50% stenosis. Only one patient (2%) had mild stenosis of the SVC. Three patients out of 15 (20%) who had diagnostic venography for the IJV had severe stenosis of the vein. Pericatheter sleeve formation was more frequent in women (P < 0.005). However, there were no statistical differences with respect to pericatheter sleeve formation, luminal filling defect and BCV stenosis when patients were grouped according to age, dwell time of the catheter, number of catheters inserted, and diameter of the SVC. Forty-two of the fifty-seven patients had had only right IJV (n =16) or right SCV (n = 26) catheters. There were no differences between these groups with respect to rates of pericatheter sleeve formation, thrombus formation, or BCV stenosis.. This study showed that even short-term catheters result in significantly high rates of pericatheter sleeve and thrombus formation which are two of the important causes of catheter malfunction. The IJV route is known to be much safer than the SCV route with respect to stenosis formation in the vein in which the catheter is inserted; however, the result showed no differences between the two routes with respect to frequencies of pericatheter sleeve formation, thrombus formation, and BCV stenosis. These findings remind us again that we should avoid unnecessary catheter insertion even for short-term in these chronically ill patients.

Topics: Adult; Aged; Aged, 80 and over; Brachiocephalic Veins; Catheterization, Central Venous; Catheters, Indwelling; Constriction, Pathologic; Contrast Media; Female; Fibrin; Foreign Bodies; Humans; Jugular Veins; Male; Middle Aged; Phlebography; Prospective Studies; Renal Dialysis; Sex Factors; Subclavian Vein; Time Factors; Vena Cava, Superior; Venous Thrombosis

Because of its high negative predictive value, D-Dimer is an important parameter in the exclusion of deep vein thrombosis (DVT) but it produces a high number of false-positive results. We therefore evaluated different blood parameters in 74 consecutive patients with suspected DVT, whose final diagnosis was based on the results of Duplex ultrasound or venography. DVT was diagnosed in 52.7%. While D-Dimer, thrombin-antithrombin complexes, prothrombin fragment 1+2, von-Willebrand factor and thrombus precursor protein were significantly increased in patients with DVT, there was no influence concerning endogenous thrombin potential and activated factor VII. There was no significant correlation between the thrombus extension or the duration of symptoms with any of these parameters. D-Dimer showed the best sensitivity (94.9%) to specificity (45.7%) ratio and neither the sole nor the additional evaluation of any other investigated parameter increased its diagnostic performance. We, therefore, conclude that the determination of D-Dimer remains the 'gold standard' in the laboratory testing of patients with suspected DVT.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Blood Coagulation Factors; Factor VIIa; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Linear Models; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; ROC Curve; Sensitivity and Specificity; Thrombin; Venous Thrombosis; von Willebrand Factor

Most animal models of venous thrombosis involve acute thrombosis with hypercoagulability in small rodents. To better replicate human disease, we developed two models in the pig, a species similar to humans in size and in vascular and coagulation reactivity. One model involves de-endothelialisation with 50% or 80% stenosis and the other replacement of a venous segment by a Gore-Tex vascular prosthesis. Both models were tested with and without acute induced hypercoagulability (thromboplastin infusion). Thrombi obtained without thromboplastin infusion were composed of a multilayered platelet and a fibrin meshwork structure similar to that usually found in humans. With thromboplastin infusion, the thrombi were homogeneous fibrin structures imprisoning red blood cells. The high incidence of thrombosis obtained with the 80% stenosis model would be useful for studying anticoagulant treatments, whereas the low incidence with 50% stenosis would be useful for evaluating procoagulant effects of conditions or treatments. These new models shed further light on the development of venous thrombi under conditions similar to those seen in humans and may prove useful for investigating anticoagulant and procoagulant effects.

Topics: Animals; Blood Vessel Prosthesis; Chronic Disease; Constriction, Pathologic; Disease Progression; Endothelium, Vascular; Fibrin; Hemorheology; Jugular Veins; Models, Animal; Swine; Thrombophilia; Thromboplastin; Venous Thrombosis

The purpose of this study was to quantify the fibrin content of thrombi produced in a mouse model of venous thrombosis and correlate this to thrombus mass. The role of P-selectin, E-selectin, and IL-10 on thrombus fibrin content was analyzed using knockout (KO) mice. Five groups of mice were evaluated: control (N = 10), P-selectin KO (N = 7), E-selectin KO (N = 5), combined E-/P-selectin KO (N = 12), and IL-10 KO (N = 10). Venous thrombosis was induced by ligation of the infrarenal IVC. Mice were sacrificed on postoperative days (POD) 2 and 6. Thrombus mass was calculated. Sections of IVC were stained with an antibody that cross reacts with mouse fibrin. The distribution of RGB color pixels was generated from digitized micrographs of the thrombus of each animal. The mean pixel value for each group was compiled and analyzed using 2-way ANOVA. Mean pixel value per group was correlated with the mean thrombus mass per group. Color analysis demonstrated significant decreases in the analyzed fibrin content on POD-2 between the control vs E-/P-selectin KO (P < 0.05) and control vs IL-10 KO (P < 0.05) groups. In addition, significantly less fibrin staining was noted on POD-6 between the control vs E-selectin KO (P = 0.03), control vs P-selectin KO (P = 0.01), and control vs E-/P-selectin KO (P < 0.01). There was a strong overall correlation between the mean pixel value for each group and the thrombus mass (R = 0.964; P < 0.01). This study demonstrates a difference in fibrin content of thrombi produced in animals deficient in E-selectin, P-selectin, and IL-10, supporting their importance in thrombus amplification, fibrin formation, and the mass of thrombus formed.

Topics: Animals; E-Selectin; Fibrin; Immunohistochemistry; Interleukin-10; Leukocyte Count; Lymphocyte Count; Mice; Mice, Knockout; Microscopy; Monocytes; Neutrophils; P-Selectin; Time Factors; Venous Thrombosis

Topics: Agglutination Tests; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Sensitivity and Specificity; Thrombin; Thromboembolism; Ultrasonography; Venous Thrombosis

The appearance of superior vena cava syndrome secondary to benign disease is rare, and it is extremely rare for this condition to develop as a result of the presence of intraluminal catheters. We report two cases of superior vena cava syndrome secondary to implantation of intracavitary pacemakers. We discuss different types of treatment.

Topics: Abscess; Aged; Catheterization, Central Venous; Catheters, Indwelling; Coronary Angiography; Fibrin; Humans; Male; Middle Aged; Pacemaker, Artificial; Staphylococcus epidermidis; Stents; Superior Vena Cava Syndrome; Vena Cava, Superior; Venous Thrombosis

Deep vein thrombosis (DVT) is a low flow pathology often prevented by vascular compression to increase blood movement. We report new heterotypic adhesive interactions of normal erythrocytes operative at low wall shear rates (gamma(w)) below 100 s(-1). Adhesion at gamma(w) = 50 s(-1) of washed red blood cells (RBCs) to fibrinogen-adherent platelets was 4-fold less (P <.005) than to collagen-adherent platelets (279 +/- 105 RBC/mm(2)). This glycoprotein VI (GPVI)-triggered adhesion was antagonized (> 80% reduction) by soluble fibrinogen (3 mg/mL) and ethylenediaminetetraacetic acid (EDTA). RBC-platelet adhesion was reduced in half by antibodies against CD36 or GPIb, but not by antibodies against GPIIb/IIIa, von Willebrand factor (VWF), thrombospondin (TSP), P-selectin, beta(1), alpha(v), or CD47. Adhesion of washed RBCs to fibrinogen-adherent neutrophils was increased 6-fold in the presence of 20 microM N-formyl-Met-Leu-Phe to a level of 67 RBCs per 100 neutrophils after 5 minutes at 50 s(-1). RBC-neutrophil adhesion was diminished by anti-CD11b (76%), anti-RBC Landsteiner-Wiener (LW) (ICAM4; 40%), or by EDTA (> 80%), but not by soluble fibrinogen or antibodies against CD11a, CD11c, CD36, TSP, beta(1), alpha(v), or CD47. RBC adhesion to activated platelets and activated neutrophils was prevented by wall shear stress above 1 dyne/cm(2) (at 100 s(-1)). Whereas washed RBCs did not adhere to fibrin formed from purified fibrinogen, adhesion was marked when pure fibrin was precoated with TSP or when RBCs were perfused over fibrin formed from recalcified plasma. Endothelial activation and unusually low flow may be a setting prone to receptor-mediated RBC adhesion to adherent neutrophils (or platelets/fibrin), all of which may contribute to DVT.

Topics: Blood Platelets; Cell Adhesion; Erythrocytes; Fibrin; Hemorheology; Hemostasis; Humans; Microscopy, Video; Neutrophil Activation; Neutrophils; P-Selectin; Plasma; Platelet Activation; Stress, Mechanical; Venous Thrombosis

In a prospective study, coagulation test results were compared in 137 patients with colorectal cancer (CRC) and 39 subjects with benign colorectal diseases. Prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), and soluble fibrin (SF) were measured in plasma before and after surgery. CRC patients presented with significantly higher values of F1+2 and TAT than controls. Patients with localised CRC had elevated values of F1+2 and TAT, whereas patients with advanced CRC also had elevated SF values. TAT and SF levels correlated with tumour spread, and normal values virtually excluded advanced cancer. Postoperative deep venous thrombosis (DVT) was diagnosed by phlebography in 20% of the CRC patients. Preoperative values of the markers did not predict postoperative DVT, but postoperative values did.

Topics: Adult; Aged; Aged, 80 and over; Antithrombin III; Biomarkers; Biomarkers, Tumor; Blood Coagulation Tests; Case-Control Studies; Colorectal Neoplasms; Female; Fibrin; Humans; Male; Middle Aged; Peptide Fragments; Peptide Hydrolases; Postoperative Complications; Predictive Value of Tests; Prospective Studies; Prothrombin; Severity of Illness Index; Venous Thrombosis

The present study aimed to assess whether the determination of overall haemostasis potential (OHP) in plasma is powerful enough to monitor the prophylactic effect of low molecular mass heparin (dalteparin, Fragmin) in patients with increased risk of thromboembolitic events. In five pregnant women who had a history of deep venous thrombosis, OHPs were kinetically investigated in gestation weeks 32-35 twice during 24 h (before injection and after 1, 2, 4, 6, 8, 10, 12, 14, 16 and 24 h). Levels of anti-activated factor X (anti-FXa), reflecting dalteparin activity, as well as prothrombin fragments 1 + 2 (F1 + 2) and soluble fibrin, were also measured. In converse relation to changes of anti-FXa, OHPs decreased reaching the lowest level between 2 and 8 h after the injection, and then rose again, returning to the levels around those before the administration. There were no significant variations in concentrations of F1 + 2 and soluble fibrin during the observation course. These findings indicate that the OHP assay can monitor the alteration of haemostatic balance under the dalteparin influence while anti-FXa only shows the activity of the drug present in plasma. Additionally, analyses of thrombin generation markers are not useful to screen immediate changes in the haemostatic system after dalteparin injection.

Topics: Adult; Anticoagulants; Biomarkers; Blood Coagulation Tests; Dalteparin; Factor Xa Inhibitors; Female; Fibrin; Fibrinolysis; Hemostasis; Humans; Pregnancy; Pregnancy Complications, Hematologic; Risk; Thrombin; Thrombophilia; Venous Thrombosis

Molecular imaging of thrombus within fissures of vulnerable atherosclerotic plaques requires sensitive detection of a robust thrombus-specific contrast agent. In this study, we report the development and characterization of a novel ligand-targeted paramagnetic molecular imaging agent with high avidity for fibrin and the potential to sensitively detect active vulnerable plaques.. The nanoparticles were formulated with 2.5 to 50 mol% Gd-DTPA-BOA, which corresponds to >50 000 Gd(3+) atoms/particle. Paramagnetic nanoparticles were characterized in vitro and evaluated in vivo. In contradistinction to traditional blood-pool agents, T1 relaxation rate as a function of paramagnetic nanoparticle number was increased monotonically with Gd-DTPA concentration from 0.18 mL. s(-1). pmol(-1) (10% Gd-DTPA nanoparticles) to 0.54 mL. s(-1). pmol(-1) for the 40 mol% Gd-DTPA formulations. Fibrin clots targeted in vitro with paramagnetic nanoparticles presented a highly detectable, homogeneous T1-weighted contrast enhancement that improved with increasing gadolinium level (0, 2.5, and 20 mol% Gd). Higher-resolution scans and scanning electron microscopy revealed that the nanoparticles were present as a thin layer over the clot surface. In vivo contrast enhancement under open-circulation conditions was assessed in dogs. The contrast-to-noise ratio between the targeted clot (20 mol% Gd-DTPA nanoparticles) and blood was approximately 118+/-21, and that between the targeted clot and the control clot was 131+/-37.. These results suggest that molecular imaging of fibrin-targeted paramagnetic nanoparticles can provide sensitive detection and localization of fibrin and may allow early, direct identification of vulnerable plaques, leading to early therapeutic decisions.

Topics: Animals; Arteriosclerosis; Biotinylation; Contrast Media; Dogs; Fibrin; Fluorocarbons; Humans; Image Enhancement; Jugular Veins; Magnetic Resonance Imaging; Microscopy, Electron, Scanning; Particle Size; Thrombosis; Venous Thrombosis

This study assessed the abundance and activity of thrombin in human thrombi. removed at autopsy or during surgery. Arterial and venous thrombus sections showed thrombin activity by in situ zymography, based on conversion of fibrinogen to fibrin. Hirudin or antibodies to thrombin abolished the activity. Thrombin activity in extracts of 40 thrombi was quantified by cleavage of fibrinogen or small peptide substrates: the results correlated well (r = 0.87, p<0.0001) with a median activity of about 4.5 IU/g of thrombus (wet weight). Activity correlated poorly with total prothrombin (median 27 microg/g) and was inversely related to antithrombin, but not to PAI-1. Zymography showed two major active bands, thrombin at 37 kDa, and a 50 kDa form that probably corresponds to meizothrombin desF1. The abundant local thrombin demonstrated here has implications for thrombus lysis and extension: incomplete lysis and exposure of active thrombin may lead to re-occlusion of vessels.

Topics: Antithrombin III; Blotting, Western; Chromogenic Compounds; Dipeptides; Enzyme-Linked Immunosorbent Assay; Fibrin; Fibrinogen; Humans; Plasminogen Activator Inhibitor 1; Prothrombin; Pulmonary Embolism; Thrombin; Venous Thrombosis

When activated in vitro, thrombin-activatable fibrinolysis inhibitor (TAFI) slows clot lysis by cleaving the C-terminal lysine and arginine residues from partially degraded fibrin. An inhibitor of carboxypeptidase isolated from potato (CPI) reverses prolongation of clot lysis by inhibiting activated TAFI. We investigated in vivo effect of TAFI inhibition on tissue-type plasminogen activator (t-PA)-induced clot lysis using CPI in a rabbit jugular vein thrombolysis model. It was found necessary to further purify the CPI preparations from commercial sources by HPLC chromatography to remove endotoxin and anti-plasmin activity that would affect the endogenous fibrinolytic system. The effect of intravenous administration of the purified CPI with t-PA was determined by measuring thrombus weight at the end of 90 minutes in six groups of animals. In the control group receiving saline, the median thrombus weight was 116 mg. In the group that received CPI only (0.5 mg/kg bolus injection followed by 0.3 mg/kg/h infusion), the median thrombus weight was 121 mg. In the group that received t-PA at a dose of 10 microg/kg bolus followed by 67 microg/kg/h infusion, the median thrombus weight decreased to 86 mg. When CPI was coadministered with the same regimen of t-PA, the median value further decreased to 58 mg. When animals were given three times higher the dose of t-PA (30 microg/kg bolus followed by 200 microg/kg/h infusion) in the absence or presence of CPI, median thrombus weights were 56 mg and 0 mg, respectively. Our results demonstrate that systemic coadministration of the purified CPI improves clot lysis induced by t-PA.

Topics: alpha-2-Antiplasmin; Animals; Carboxypeptidase B2; Carboxypeptidases; Chromatography, High Pressure Liquid; Drug Evaluation, Preclinical; Drug Synergism; Endothelium, Vascular; Enzyme Activation; Fibrin; Fibrinogen; Fibrinolysis; Infusions, Intravenous; Plant Proteins; Plasminogen; Protease Inhibitors; Rabbits; Solanum tuberosum; Thrombin; Thrombolytic Therapy; Tissue Plasminogen Activator; Venous Thrombosis

Thrombolysis protects the structural and functional integrity of vein wall in an experimental model of acute deep venous thrombosis (DVT) immediately after treatment, but late sequelae have not been studied. We designed experiments to compare the effects of thrombolysis and surgical thrombectomy at 4 weeks after the treatment of DVT.. DVT was produced bilaterally in male mongrel dogs by proximal and distal femoral vein ligation. Five dogs underwent sham operation. After 48 hours, the ligatures were removed, and the thrombosis was treated with either Fogarty balloon catheter thrombectomy (shear force, 60 g; n = 6) or catheter-directed urokinase infusion (4000 U/min for 90 minutes; n = 6). At 4 weeks, patency and valvular competence were determined by duplex ultrasound scanning. Thrombogenicity was studied by the measurement of radiolabeled fibrin and platelet deposition. Veins were explanted and prepared for histologic examination, scanning electron microscopy, and functional studies in organ chambers.. All veins were patent at 1 month. Recanalized thrombus was observed histologically in four (66%) thrombectomized veins, one (17%) thrombolyzed vein, and none of the sham-operated veins (P =.04). Scanning electron microscopy demonstrated similar luminal endothelial cell loss (11%-25%) in all three groups. Platelet and fibrin depositions were not different among groups. Valvular incompetence (reflux duration, >0.5 sec) did not differ significantly in the groups (thrombectomized veins, 2 of 12 (17%); thrombolyzed veins, 0 of 12 (0%); P = NS). In organ chamber studies, endothelium-dependent relaxations to calcium ionophore, but not adenosine diphosphate, were inhibited by an antagonist of nitric oxide production after thrombectomy (P <.05, thrombectomy vs sham- and thrombolysis-treated veins). All veins relaxed to exogenous nitric oxide.. Both thrombectomy and thrombolysis restored patency and achieved similar valvular competence. Surgical thrombectomy, however, resulted in more residual thrombus and contributed to changes in endothelium-mediated relaxations at 4 weeks. Thrombolysis maintained both structural integrity and endothelial function.

Topics: Adenosine Diphosphate; Analysis of Variance; Animals; Calcimycin; Catheterization; Dogs; Endothelium, Vascular; Femoral Vein; Fibrin; Ionophores; Ligation; Male; Microscopy, Electron, Scanning; Nitric Oxide; Plasminogen Activators; Platelet Adhesiveness; Thrombectomy; Thrombolytic Therapy; Treatment Outcome; Ultrasonography, Doppler, Duplex; Urokinase-Type Plasminogen Activator; Vascular Patency; Vasodilator Agents; Vasomotor System; Venous Thrombosis

The trial included ninety-five consecutive outpatients admitted with symptoms and signs suggesting deep venous thrombosis. Blood samples were collected on admission and analysed when the trial was ended. The three different D-dimer methods were BC D-dimer, Tinaquant D-dimer (both quantitative latex agglutination methods) and VIDAS D-dimer, based on the ELISA principle. Ultrasound was used as the reference method, but the outcome evaluated at three month follow up was the gold standard. The sensitivities of the three different methods were 66% (95% confidence interval 55-75%), 93% (88-98%) and 98% (94-100%) respectively. The negative predictive values were respectively 71% (62-80%), 88% (81-95%) and 95% (91-99%). This trial confirms that VIDAS D-dimer has a high sensitivity and negative predictive value that makes it suitable for clinical use. The same conclusion can be drawn for the Tinaquant D-dimer. The trial also emphasizes the importance of testing new methods under routine clinical conditions.

Topics: Adult; Biomarkers; Blood Coagulation Tests; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Hemagglutination Tests; Humans; Male; Middle Aged; Sensitivity and Specificity; Venous Thrombosis

Topics: Adult; Anticoagulants; Drug Interactions; Emergencies; Female; Fibrin; Humans; Levonorgestrel; Pulmonary Embolism; Venous Thrombosis; Warfarin

Few data exist by which the anti-thrombotic efficacy of different anticoagulants may be compared. We used a radiolabeled antibody specific for polymerizing fibrin to compare the in vivo anti-thrombotic potencies of different systemic anticoagulants (enoxaparin, dalteparin, and unfractionated heparin).. Deep venous thrombi (DVTs) were induced in dogs' femoral veins. The dogs were then treated with one of the following subcutaneous regimens: enoxaparin 100 units/kg (1.0 mg/kg) every 12 hours (n=4), dalteparin 200 units/kg every 24 hours (n=4), or unfractionated heparin 240 units/kg every 8 hours with dose adjustment via aPTT (n=3). 111Indium-labeled anti-fibrin antibodies, specific for propagating thrombi, were given intravenously and nuclear scans of the legs were taken over the following 24 hours. Thrombus propagation was estimated by the ratio of gamma emissions from the legs containing DVTs divided by the emissions from the contralateral "control" legs. DVTs accumulated labeled anti-fibrin antibodies at the same rates in both the enoxaparin group and the dalteparin group (gamma emissions 171+/-6% and 168+/-36% of control by 24 hours, respectively). DVTs in the adjusted dose unfractionated heparin group tended to accumulate antibodies at a slower rate (129+/-19% of control by 24 hours).. Enoxaparin and dalteparin inhibited propagation of pre-formed thrombi to the same degree. Subcutaneous unfractionated heparin, adjusted every 8 hours by aPTT, tended to suppress ongoing thrombosis more than either LMWH.

Topics: Animals; Antibodies; Anticoagulants; Balloon Occlusion; Dalteparin; Diagnostic Imaging; Disease Models, Animal; Dogs; Drug Evaluation, Preclinical; Enoxaparin; Factor Xa; Factor Xa Inhibitors; Femur; Fibrin; Gamma Rays; Heparin; Heparin, Low-Molecular-Weight; Indium Radioisotopes; Prothrombin; Thromboembolism; Venous Thrombosis

Heparin cofactor II (HCII) is a specific inhibitor of thrombin in the presence of heparin or dermatan sulphate. Although there have been reports on families in which a heterozygous HCII deficiency is associated with thromboembolic events, several epidemiological studies revealed that heterozygous HCII deficiency is as prevalent among healthy subjects as it is among patients with deep venous thrombosis (DVT). It is therefore not yet clear whether HCII is or is not a thrombotic risk factor. We analyze and describe in an extended family the biochemical and genetic thrombophilic risk factors and evaluate the potential thrombotic risk involved in homozygous and heterozygous HCII deficiency, either alone or associated with other thrombotic or circumstantial risk factors. The propositus has had three episodes of DVT and a pulmonary embolism. During the first episode of DVT the patient was diagnosed as having AT deficiency. Later, a functional and antigenic HCII deficiency, compatible with the homozygous form, was detected. The family study shows that both the propositus and her sister have homozygous HCII deficiency and that 12 of the 27 family members have heterozygous HCII deficiency. This is possibly the first case report on a homozygous phenotype for the HCII deficiency with. in addition, partial AT deficiency. The propositus has suffered several thrombotic events, unlike the other 12 family members with heterozygous HCII deficiency and her sister, who is also homozygous for this disorder. We suggest that HCII deficiency may play a limited in vivo role as a thrombotic risk factor unless associated with AT deficiency or another congenital thrombotic risk factor.

Topics: Adolescent; Adult; Anticoagulants; Child; Child, Preschool; Female; Fibrin; Heparin Cofactor II; Heterozygote; Homozygote; Humans; Infant; Male; Middle Aged; Pedigree; Phenotype; Pregnancy; Pregnancy Complications, Hematologic; Pulmonary Embolism; Risk Factors; Venous Thrombosis

To evaluate the thrombolytic efficacy of bispecfic antifibrin-antiurokinase monoclonal antibodies.. Murine hybrid hybridomas secreting bispecific monoclonal antibodies (bsMcAbs) were prepared by fusing a mutant hybridomas secreting antifibrin McAbs with spleen cells of murine immunized with urokinase. The binding power of bsMcAbs with fibrin or urokinase was determined by ELISA method. The in vitro thrombolytic efficacy was measured by the dissolving rate of 131I-plasma clot. The in vivo thrombolytic efficacy was measured by using the rabbit jugular vein thrombus model.. 8 strains of bsMcAbs have been obtained. ELISA experiments showed that bsMcAbs have very strong binding power with fibrin or urokinase. The bsMcAbs bound with urokinase increased the in vitro thrombolytic efficacy of urokinase by 15.5%. The in vivo thrombolytic efficacy of bsMcAbs bound with urokinase was 1.6-2.1 times as high as urokinase.. Monoclonal antibody-directed thrombolytic agents have advantages of high specificity and strong local thrombolytic efficacy. It is well worth going on further study.

Topics: Animals; Antibodies, Bispecific; Antibodies, Monoclonal; Cell Fusion; Fibrin; Fibrinolytic Agents; Hybridomas; Mice; Mice, Inbred BALB C; Rabbits; Spleen; Urokinase-Type Plasminogen Activator; Venous Thrombosis